Message ID | 20221112212943.3068249-8-philipp.tomsich@vrull.eu |
---|---|
State | New |
Headers | show |
Series | RISC-V: Backend support for XVentanaCondOps/ZiCondops | expand |
On Sat, Nov 12, 2022 at 1:34 PM Philipp Tomsich <philipp.tomsich@vrull.eu> wrote: > > Some architectures, as it the case on RISC-V with the proposed > ZiCondOps and the vendor-defined XVentanaCondOps, define a > conditional-zero instruction that is equivalent to: > - the positive form: rd = (rc != 0) ? rs : 0 > - the negated form: rd = (rc == 0) ? rs : 0 > > While noce_try_store_flag_mask will somewhat work for this case, it > will generate a number of atomic RTX that will misdirect the cost > calculation and may be too long (i.e., 4 RTX and more) to successfully > merge at combine-time. > > Instead, we add two new transforms that attempt to build up what we > define as the canonical form of a conditional-zero expression: > > (set (match_operand 0 "register_operand" "=r") > (and (neg (eq_or_ne (match_operand 1 "register_operand" "r") > (const_int 0))) > (match_operand 2 "register_operand" "r"))) Why is it not: (set x (if_then_else (eq_or_ne y (0)) z (0)) (set x (if_then_else (ne y (0)) (0) z) That seems simpler to expression and is the normal a==0?0:z expression. Also all canonical forms of RTL should be documented too. They are documented here: https://gcc.gnu.org/onlinedocs/gcc-12.2.0/gccint/Insn-Canonicalizations.html https://gcc.gnu.org/onlinedocs/gccint/machine-descriptions/canonicalization-of-instructions.html gcc/doc/gccint/machine-descriptions/canonicalization-of-instructions.rst Thanks, Andrew Pinski > > Architectures that provide a conditional-zero are thus expected to > define an instruction matching this pattern in their backend. > > Based on this, we support the following cases: > - noce_try_condzero: > a ? a : b > a ? b : 0 (and then/else swapped) > !a ? b : 0 (and then/else swapped) > - noce_try_condzero_arith: > conditional-plus, conditional-minus, conditional-and, > conditional-or, conditional-xor, conditional-shift, > conditional-and > > Given that this is hooked into the CE passes, it is less powerful than > a tree-pass (e.g., it can not transform cases where an extension, such > as for uint16_t operations is in either the then or else-branch > together with the arithmetic) but already covers a good array of cases > and triggers across SPEC CPU 2017. > Adding transofmrations in a tree pass will be considered as a future > improvement. > > gcc/ChangeLog: > > * ifcvt.cc (noce_emit_insn): Add prototype. > (noce_emit_condzero): Helper for noce_try_condzero and > noce_try_condzero_arith transforms. > (noce_try_condzero): New transform. > (noce_try_condzero_arith): New transform for conditional > arithmetic that can be built up by exploiting that the > conditional-zero instruction will inject 0, which acts > as the neutral element for operations. > (noce_process_if_block): Call noce_try_condzero and > noce_try_condzero_arith. > > gcc/testsuite/ChangeLog: > > * gcc.target/riscv/xventanacondops-and-01.c: New test. > * gcc.target/riscv/xventanacondops-and-02.c: New test. > * gcc.target/riscv/xventanacondops-eq-01.c: New test. > * gcc.target/riscv/xventanacondops-eq-02.c: New test. > * gcc.target/riscv/xventanacondops-lt-01.c: New test. > * gcc.target/riscv/xventanacondops-ne-01.c: New test. > * gcc.target/riscv/xventanacondops-xor-01.c: New test. > > Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu> > --- > > gcc/ifcvt.cc | 214 ++++++++++++++++++ > .../gcc.target/riscv/xventanacondops-and-01.c | 16 ++ > .../gcc.target/riscv/xventanacondops-and-02.c | 15 ++ > .../gcc.target/riscv/xventanacondops-eq-01.c | 11 + > .../gcc.target/riscv/xventanacondops-eq-02.c | 14 ++ > .../gcc.target/riscv/xventanacondops-lt-01.c | 16 ++ > .../gcc.target/riscv/xventanacondops-ne-01.c | 11 + > .../gcc.target/riscv/xventanacondops-xor-01.c | 14 ++ > 8 files changed, 311 insertions(+) > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c > > diff --git a/gcc/ifcvt.cc b/gcc/ifcvt.cc > index eb8efb89a89..41c58876d05 100644 > --- a/gcc/ifcvt.cc > +++ b/gcc/ifcvt.cc > @@ -97,6 +97,7 @@ static int find_if_case_2 (basic_block, edge, edge); > static int dead_or_predicable (basic_block, basic_block, basic_block, > edge, int); > static void noce_emit_move_insn (rtx, rtx); > +static rtx_insn *noce_emit_insn (rtx); > static rtx_insn *block_has_only_trap (basic_block); > static void need_cmov_or_rewire (basic_block, hash_set<rtx_insn *> *, > hash_map<rtx_insn *, int> *); > @@ -787,6 +788,9 @@ static rtx noce_get_alt_condition (struct noce_if_info *, rtx, rtx_insn **); > static int noce_try_minmax (struct noce_if_info *); > static int noce_try_abs (struct noce_if_info *); > static int noce_try_sign_mask (struct noce_if_info *); > +static rtx noce_emit_condzero (struct noce_if_info *, rtx, bool = false); > +static int noce_try_condzero (struct noce_if_info *); > +static int noce_try_condzero_arith (struct noce_if_info *); > > /* Return the comparison code for reversed condition for IF_INFO, > or UNKNOWN if reversing the condition is not possible. */ > @@ -1664,6 +1668,212 @@ noce_try_addcc (struct noce_if_info *if_info) > return FALSE; > } > > +/* Helper to noce_try_condzero: cond ? a : 0. */ > +static rtx > +noce_emit_condzero (struct noce_if_info *if_info, rtx a, bool reverse) > +{ > + /* The canonical form for a conditional-zero-or-value is: > + (set (match_operand 0 "register_operand" "=r") > + (and (neg (eq_or_ne (match_operand 1 "register_operand" "r") > + (const_int 0))) > + (match_operand 2 "register_operand" "r"))) > + */ > + > + machine_mode opmode = GET_MODE (if_info->x); > + enum rtx_code code = GET_CODE (if_info->cond); > + rtx cond; > + rtx op_a = XEXP (if_info->cond, 0); > + rtx op_b = XEXP (if_info->cond, 1); > + > + /* If it is not a EQ/NE comparison against const0_rtx, canonicalize > + by first synthesizing a truth-value and then building a NE > + condition around it. */ > + if ((code != EQ && code != NE) || XEXP (if_info->cond, 1) != const0_rtx) > + { > + rtx tmp = gen_reg_rtx (opmode); > + > + start_sequence (); > + cond = gen_rtx_fmt_ee (code, opmode, op_a, op_b); > + if (!noce_emit_insn (gen_rtx_SET (tmp, cond))) > + { > + end_sequence (); > + > + /* If we can't emit this pattern, try to reverse it and > + invert the polarity of the second test. */ > + start_sequence (); > + cond = gen_rtx_fmt_ee (reverse_condition (code), opmode, op_a, op_b); > + if (!noce_emit_insn (gen_rtx_SET (tmp, cond))) { > + end_sequence (); > + return NULL_RTX; > + } > + > + /* We have recovered by reversing the first comparison, > + so we need change the second one around as well... */ > + reverse = !reverse; > + } > + rtx_insn *seq = get_insns (); > + end_sequence (); > + emit_insn (seq); > + > + /* Set up the second comparison that will be embedded in the > + canonical conditional-zero-or-value RTX. */ > + code = NE; > + op_a = tmp; > + op_b = const0_rtx; > + } > + > + cond = gen_rtx_fmt_ee (reverse ? reverse_condition (code) : code, > + opmode, op_a, op_b); > + > + /* Build (and (neg (eq_or_ne ... const0_rtx)) (reg <a>)) */ > + rtx target = gen_reg_rtx (opmode); > + rtx czero = gen_rtx_AND (opmode, gen_rtx_NEG (opmode, cond), a); > + noce_emit_move_insn (target, czero); > + > + return target; > +} > + > +/* Use a conditional-zero instruction for "if (test) x = 0;", if available. */ > +static int > +noce_try_condzero (struct noce_if_info *if_info) > +{ > + rtx target; > + rtx_insn *seq; > + int reversep = 0; > + rtx orig_b = NULL_RTX; > + rtx cond = if_info->cond; > + enum rtx_code code = GET_CODE (cond); > + rtx cond_arg0 = XEXP (cond, 0); > + rtx cond_arg1 = XEXP (cond, 1); > + > + if (!noce_simple_bbs (if_info)) > + return FALSE; > + > + /* We may encounter the form "(a != 0) ? a : b", which can be > + simplified to "a | ((a != 0) ? 0 : b)". */ > + if (code == NE && cond_arg1 == const0_rtx && > + REG_P (if_info->b) && rtx_equal_p (if_info->b, cond_arg0)) > + { > + orig_b = if_info->b; > + if_info->b = const0_rtx; > + } > + > + /* We may encounter the form "(a != 0) ? b : a", which can be > + simplied to "(a != 0) ? b : 0". */ > + if (code == EQ && cond_arg1 == const0_rtx && > + REG_P (if_info->b) && rtx_equal_p (if_info->b, cond_arg0)) > + { > + /* We know that cond_arg0 is const_0, if the THEN branch is > + taken... so if it is the same as if_info->b (yes, things are > + backwards!), we can rewrite it with that knowledge. */ > + if_info->b = const0_rtx; > + } > + > + start_sequence (); > + > + if ((if_info->a == const0_rtx > + && (REG_P (if_info->b) || rtx_equal_p (if_info->b, if_info->x))) > + || ((reversep = (noce_reversed_cond_code (if_info) != UNKNOWN)) > + && if_info->b == const0_rtx > + && (REG_P (if_info->a) || rtx_equal_p (if_info->a, if_info->x)))) > + { > + target = noce_emit_condzero(if_info, > + reversep ? if_info->a : if_info->b, > + reversep); > + > + if (orig_b && target) > + target = expand_simple_binop (GET_MODE (if_info->x), IOR, orig_b, > + target, if_info->x, 0, OPTAB_WIDEN); > + > + if (target) > + { > + if (target != if_info->x) > + noce_emit_move_insn (if_info->x, target); > + > + seq = end_ifcvt_sequence (if_info); > + if (!seq || !targetm.noce_conversion_profitable_p (seq, if_info)) > + return FALSE; > + > + emit_insn_before_setloc (seq, if_info->jump, > + INSN_LOCATION (if_info->insn_a)); > + if_info->transform_name = "noce_try_condzero"; > + > + return TRUE; > + } > + } > + > + end_sequence (); > + > + return FALSE; > +} > + > +/* Convert "if (test) x op= a;" to a branchless sequence using the > + canonical form for a conditional-zero. */ > +static int > +noce_try_condzero_arith (struct noce_if_info *if_info) > +{ > + rtx target; > + rtx_insn *seq; > + rtx_code op = GET_CODE (if_info->a); > + const rtx arg0 = XEXP (if_info->a, 0); > + const rtx arg1 = XEXP (if_info->a, 1); > + > + if (!noce_simple_bbs (if_info)) > + return FALSE; > + > + /* Check for no else condition. */ > + if (!rtx_equal_p (if_info->x, if_info->b)) > + return FALSE; > + > + if (op != PLUS && op != MINUS && op != IOR && op != XOR && > + op != ASHIFT && op != ASHIFTRT && op != LSHIFTRT && op != AND) > + return FALSE; > + > + if (!rtx_equal_p (if_info->x, arg0)) > + return FALSE; > + > + start_sequence (); > + > + target = noce_emit_condzero(if_info, arg1, op != AND ? true : false); > + > + if (target) > + { > + rtx op1 = if_info->x; > + > + if (op == AND) > + { > + /* Emit "tmp = x & val;" followed by "tmp |= !cond ? x : 0;" */ > + op1 = expand_simple_binop (GET_MODE (if_info->x), AND, op1, > + arg1, NULL_RTX, 0, OPTAB_WIDEN); > + op = IOR; > + } > + > + if (op1) > + target = expand_simple_binop (GET_MODE (if_info->x), op, op1, > + target, if_info->x, 0, OPTAB_WIDEN); > + } > + > + if (target) > + { > + if (target != if_info->x) > + noce_emit_move_insn (if_info->x, target); > + > + seq = end_ifcvt_sequence (if_info); > + if (!seq || !targetm.noce_conversion_profitable_p (seq, if_info)) > + return FALSE; > + > + emit_insn_before_setloc(seq, if_info->jump, > + INSN_LOCATION(if_info->insn_a)); > + if_info->transform_name = "noce_try_condzero_arith"; > + > + return TRUE; > + } > + > + end_sequence (); > + > + return FALSE; > +} > + > /* Convert "if (test) x = 0;" to "x &= -(test == 0);" */ > > static int > @@ -3967,8 +4177,12 @@ noce_process_if_block (struct noce_if_info *if_info) > { > if (noce_try_addcc (if_info)) > goto success; > + if (noce_try_condzero (if_info)) > + goto success; > if (noce_try_store_flag_mask (if_info)) > goto success; > + if (noce_try_condzero_arith (if_info)) > + goto success; > if (HAVE_conditional_move > && noce_try_cmove_arith (if_info)) > goto success; > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c > new file mode 100644 > index 00000000000..9b26cdf0513 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c > @@ -0,0 +1,16 @@ > +/* { dg-do compile } */ > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ > + > +long and1(long a, long b, long c, long d) > +{ > + if (c < d) > + a &= b; > + > + return a; > +} > + > +/* { dg-final { scan-assembler-times "and\t" 1 } } */ > +/* { dg-final { scan-assembler-times "slt" 1 } } */ > +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ > +/* { dg-final { scan-assembler-times "or\t" 1 } } */ > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c > new file mode 100644 > index 00000000000..66d2ec10211 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c > @@ -0,0 +1,15 @@ > +/* { dg-do compile } */ > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ > + > +int and2(int a, int b, long c) > +{ > + if (c) > + a &= b; > + > + return a; > +} > + > +/* { dg-final { scan-assembler-times "and\t" 1 } } */ > +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ > +/* { dg-final { scan-assembler-times "or\t" 1 } } */ > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c > new file mode 100644 > index 00000000000..bc877d9e81b > --- /dev/null > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c > @@ -0,0 +1,11 @@ > +/* { dg-do compile } */ > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" } } */ > + > +long > +eq1 (long a, long b) > +{ > + return (a == 0) ? b : 0; > +} > + > +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c > new file mode 100644 > index 00000000000..28317613ba8 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c > @@ -0,0 +1,14 @@ > +/* { dg-do compile } */ > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" } } */ > + > +long > +eq2 (long a, long b) > +{ > + if (a == 0) > + return b; > + > + return 0; > +} > + > +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c > new file mode 100644 > index 00000000000..db7498801f9 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c > @@ -0,0 +1,16 @@ > +/* { dg-do compile } */ > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ > + > +long long sink (long long); > + > +long long lt3 (long long a, long long b) > +{ > + if (a < b) > + b = 0; > + > + return sink(b); > +} > + > +/* { dg-final { scan-assembler-times "vt.maskcn\" 1 } } */ > +/* { dg-final { scan-assembler-times "slt\t" 1 } } */ > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c > new file mode 100644 > index 00000000000..eff1486828c > --- /dev/null > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c > @@ -0,0 +1,11 @@ > +/* { dg-do compile } */ > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" } } */ > + > +long long ne1(long long a, long long b) > +{ > + return (a != 0) ? b : 0; > +} > + > +/* { dg-final { scan-assembler-times "vt.maskc" 1 } } */ > + > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c > new file mode 100644 > index 00000000000..43020790a22 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c > @@ -0,0 +1,14 @@ > +/* { dg-do compile } */ > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ > + > +long xor1(long crc, long poly) > +{ > + if (crc & 1) > + crc ^= poly; > + > + return crc; > +} > + > +/* { dg-final { scan-assembler-times "vt.maskc" 1 } } */ > +/* { dg-final { scan-assembler-times "xor\t" 1 } } */ > -- > 2.34.1 >
On Sat, 12 Nov 2022 at 22:47, Andrew Pinski <pinskia@gmail.com> wrote: > > On Sat, Nov 12, 2022 at 1:34 PM Philipp Tomsich > <philipp.tomsich@vrull.eu> wrote: > > > > Some architectures, as it the case on RISC-V with the proposed > > ZiCondOps and the vendor-defined XVentanaCondOps, define a > > conditional-zero instruction that is equivalent to: > > - the positive form: rd = (rc != 0) ? rs : 0 > > - the negated form: rd = (rc == 0) ? rs : 0 > > > > While noce_try_store_flag_mask will somewhat work for this case, it > > will generate a number of atomic RTX that will misdirect the cost > > calculation and may be too long (i.e., 4 RTX and more) to successfully > > merge at combine-time. > > > > Instead, we add two new transforms that attempt to build up what we > > define as the canonical form of a conditional-zero expression: > > > > (set (match_operand 0 "register_operand" "=r") > > (and (neg (eq_or_ne (match_operand 1 "register_operand" "r") > > (const_int 0))) > > (match_operand 2 "register_operand" "r"))) > > > Why is it not: > (set x (if_then_else (eq_or_ne y (0)) z (0)) > (set x (if_then_else (ne y (0)) (0) z) > > That seems simpler to expression and is the normal a==0?0:z expression. Having an if_then_else come out of if-conversion would be a bit unusual, as transformation to branchless is the intent of the entire exercise. Existing if-conversion via noce_try_store_flag_mask and noce_try_store_flag already catch these sequences—if that happens, the above representation will be present during combine: i.e., we need to implement this match anyway (and it also matches the typical idiom, if a programmer tries to express the idiom in a branchless way). Consequently, we decided to use the same pattern as the canonical representation in case that if-conversion had occurred prior. > Also all canonical forms of RTL should be documented too. > They are documented here: > https://gcc.gnu.org/onlinedocs/gcc-12.2.0/gccint/Insn-Canonicalizations.html > https://gcc.gnu.org/onlinedocs/gccint/machine-descriptions/canonicalization-of-instructions.html > gcc/doc/gccint/machine-descriptions/canonicalization-of-instructions.rst > > > Thanks, > Andrew Pinski > > > > > Architectures that provide a conditional-zero are thus expected to > > define an instruction matching this pattern in their backend. > > > > Based on this, we support the following cases: > > - noce_try_condzero: > > a ? a : b > > a ? b : 0 (and then/else swapped) > > !a ? b : 0 (and then/else swapped) > > - noce_try_condzero_arith: > > conditional-plus, conditional-minus, conditional-and, > > conditional-or, conditional-xor, conditional-shift, > > conditional-and > > > > Given that this is hooked into the CE passes, it is less powerful than > > a tree-pass (e.g., it can not transform cases where an extension, such > > as for uint16_t operations is in either the then or else-branch > > together with the arithmetic) but already covers a good array of cases > > and triggers across SPEC CPU 2017. > > Adding transofmrations in a tree pass will be considered as a future > > improvement. > > > > gcc/ChangeLog: > > > > * ifcvt.cc (noce_emit_insn): Add prototype. > > (noce_emit_condzero): Helper for noce_try_condzero and > > noce_try_condzero_arith transforms. > > (noce_try_condzero): New transform. > > (noce_try_condzero_arith): New transform for conditional > > arithmetic that can be built up by exploiting that the > > conditional-zero instruction will inject 0, which acts > > as the neutral element for operations. > > (noce_process_if_block): Call noce_try_condzero and > > noce_try_condzero_arith. > > > > gcc/testsuite/ChangeLog: > > > > * gcc.target/riscv/xventanacondops-and-01.c: New test. > > * gcc.target/riscv/xventanacondops-and-02.c: New test. > > * gcc.target/riscv/xventanacondops-eq-01.c: New test. > > * gcc.target/riscv/xventanacondops-eq-02.c: New test. > > * gcc.target/riscv/xventanacondops-lt-01.c: New test. > > * gcc.target/riscv/xventanacondops-ne-01.c: New test. > > * gcc.target/riscv/xventanacondops-xor-01.c: New test. > > > > Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu> > > --- > > > > gcc/ifcvt.cc | 214 ++++++++++++++++++ > > .../gcc.target/riscv/xventanacondops-and-01.c | 16 ++ > > .../gcc.target/riscv/xventanacondops-and-02.c | 15 ++ > > .../gcc.target/riscv/xventanacondops-eq-01.c | 11 + > > .../gcc.target/riscv/xventanacondops-eq-02.c | 14 ++ > > .../gcc.target/riscv/xventanacondops-lt-01.c | 16 ++ > > .../gcc.target/riscv/xventanacondops-ne-01.c | 11 + > > .../gcc.target/riscv/xventanacondops-xor-01.c | 14 ++ > > 8 files changed, 311 insertions(+) > > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c > > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c > > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c > > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c > > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c > > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c > > create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c > > > > diff --git a/gcc/ifcvt.cc b/gcc/ifcvt.cc > > index eb8efb89a89..41c58876d05 100644 > > --- a/gcc/ifcvt.cc > > +++ b/gcc/ifcvt.cc > > @@ -97,6 +97,7 @@ static int find_if_case_2 (basic_block, edge, edge); > > static int dead_or_predicable (basic_block, basic_block, basic_block, > > edge, int); > > static void noce_emit_move_insn (rtx, rtx); > > +static rtx_insn *noce_emit_insn (rtx); > > static rtx_insn *block_has_only_trap (basic_block); > > static void need_cmov_or_rewire (basic_block, hash_set<rtx_insn *> *, > > hash_map<rtx_insn *, int> *); > > @@ -787,6 +788,9 @@ static rtx noce_get_alt_condition (struct noce_if_info *, rtx, rtx_insn **); > > static int noce_try_minmax (struct noce_if_info *); > > static int noce_try_abs (struct noce_if_info *); > > static int noce_try_sign_mask (struct noce_if_info *); > > +static rtx noce_emit_condzero (struct noce_if_info *, rtx, bool = false); > > +static int noce_try_condzero (struct noce_if_info *); > > +static int noce_try_condzero_arith (struct noce_if_info *); > > > > /* Return the comparison code for reversed condition for IF_INFO, > > or UNKNOWN if reversing the condition is not possible. */ > > @@ -1664,6 +1668,212 @@ noce_try_addcc (struct noce_if_info *if_info) > > return FALSE; > > } > > > > +/* Helper to noce_try_condzero: cond ? a : 0. */ > > +static rtx > > +noce_emit_condzero (struct noce_if_info *if_info, rtx a, bool reverse) > > +{ > > + /* The canonical form for a conditional-zero-or-value is: > > + (set (match_operand 0 "register_operand" "=r") > > + (and (neg (eq_or_ne (match_operand 1 "register_operand" "r") > > + (const_int 0))) > > + (match_operand 2 "register_operand" "r"))) > > + */ > > + > > + machine_mode opmode = GET_MODE (if_info->x); > > + enum rtx_code code = GET_CODE (if_info->cond); > > + rtx cond; > > + rtx op_a = XEXP (if_info->cond, 0); > > + rtx op_b = XEXP (if_info->cond, 1); > > + > > + /* If it is not a EQ/NE comparison against const0_rtx, canonicalize > > + by first synthesizing a truth-value and then building a NE > > + condition around it. */ > > + if ((code != EQ && code != NE) || XEXP (if_info->cond, 1) != const0_rtx) > > + { > > + rtx tmp = gen_reg_rtx (opmode); > > + > > + start_sequence (); > > + cond = gen_rtx_fmt_ee (code, opmode, op_a, op_b); > > + if (!noce_emit_insn (gen_rtx_SET (tmp, cond))) > > + { > > + end_sequence (); > > + > > + /* If we can't emit this pattern, try to reverse it and > > + invert the polarity of the second test. */ > > + start_sequence (); > > + cond = gen_rtx_fmt_ee (reverse_condition (code), opmode, op_a, op_b); > > + if (!noce_emit_insn (gen_rtx_SET (tmp, cond))) { > > + end_sequence (); > > + return NULL_RTX; > > + } > > + > > + /* We have recovered by reversing the first comparison, > > + so we need change the second one around as well... */ > > + reverse = !reverse; > > + } > > + rtx_insn *seq = get_insns (); > > + end_sequence (); > > + emit_insn (seq); > > + > > + /* Set up the second comparison that will be embedded in the > > + canonical conditional-zero-or-value RTX. */ > > + code = NE; > > + op_a = tmp; > > + op_b = const0_rtx; > > + } > > + > > + cond = gen_rtx_fmt_ee (reverse ? reverse_condition (code) : code, > > + opmode, op_a, op_b); > > + > > + /* Build (and (neg (eq_or_ne ... const0_rtx)) (reg <a>)) */ > > + rtx target = gen_reg_rtx (opmode); > > + rtx czero = gen_rtx_AND (opmode, gen_rtx_NEG (opmode, cond), a); > > + noce_emit_move_insn (target, czero); > > + > > + return target; > > +} > > + > > +/* Use a conditional-zero instruction for "if (test) x = 0;", if available. */ > > +static int > > +noce_try_condzero (struct noce_if_info *if_info) > > +{ > > + rtx target; > > + rtx_insn *seq; > > + int reversep = 0; > > + rtx orig_b = NULL_RTX; > > + rtx cond = if_info->cond; > > + enum rtx_code code = GET_CODE (cond); > > + rtx cond_arg0 = XEXP (cond, 0); > > + rtx cond_arg1 = XEXP (cond, 1); > > + > > + if (!noce_simple_bbs (if_info)) > > + return FALSE; > > + > > + /* We may encounter the form "(a != 0) ? a : b", which can be > > + simplified to "a | ((a != 0) ? 0 : b)". */ > > + if (code == NE && cond_arg1 == const0_rtx && > > + REG_P (if_info->b) && rtx_equal_p (if_info->b, cond_arg0)) > > + { > > + orig_b = if_info->b; > > + if_info->b = const0_rtx; > > + } > > + > > + /* We may encounter the form "(a != 0) ? b : a", which can be > > + simplied to "(a != 0) ? b : 0". */ > > + if (code == EQ && cond_arg1 == const0_rtx && > > + REG_P (if_info->b) && rtx_equal_p (if_info->b, cond_arg0)) > > + { > > + /* We know that cond_arg0 is const_0, if the THEN branch is > > + taken... so if it is the same as if_info->b (yes, things are > > + backwards!), we can rewrite it with that knowledge. */ > > + if_info->b = const0_rtx; > > + } > > + > > + start_sequence (); > > + > > + if ((if_info->a == const0_rtx > > + && (REG_P (if_info->b) || rtx_equal_p (if_info->b, if_info->x))) > > + || ((reversep = (noce_reversed_cond_code (if_info) != UNKNOWN)) > > + && if_info->b == const0_rtx > > + && (REG_P (if_info->a) || rtx_equal_p (if_info->a, if_info->x)))) > > + { > > + target = noce_emit_condzero(if_info, > > + reversep ? if_info->a : if_info->b, > > + reversep); > > + > > + if (orig_b && target) > > + target = expand_simple_binop (GET_MODE (if_info->x), IOR, orig_b, > > + target, if_info->x, 0, OPTAB_WIDEN); > > + > > + if (target) > > + { > > + if (target != if_info->x) > > + noce_emit_move_insn (if_info->x, target); > > + > > + seq = end_ifcvt_sequence (if_info); > > + if (!seq || !targetm.noce_conversion_profitable_p (seq, if_info)) > > + return FALSE; > > + > > + emit_insn_before_setloc (seq, if_info->jump, > > + INSN_LOCATION (if_info->insn_a)); > > + if_info->transform_name = "noce_try_condzero"; > > + > > + return TRUE; > > + } > > + } > > + > > + end_sequence (); > > + > > + return FALSE; > > +} > > + > > +/* Convert "if (test) x op= a;" to a branchless sequence using the > > + canonical form for a conditional-zero. */ > > +static int > > +noce_try_condzero_arith (struct noce_if_info *if_info) > > +{ > > + rtx target; > > + rtx_insn *seq; > > + rtx_code op = GET_CODE (if_info->a); > > + const rtx arg0 = XEXP (if_info->a, 0); > > + const rtx arg1 = XEXP (if_info->a, 1); > > + > > + if (!noce_simple_bbs (if_info)) > > + return FALSE; > > + > > + /* Check for no else condition. */ > > + if (!rtx_equal_p (if_info->x, if_info->b)) > > + return FALSE; > > + > > + if (op != PLUS && op != MINUS && op != IOR && op != XOR && > > + op != ASHIFT && op != ASHIFTRT && op != LSHIFTRT && op != AND) > > + return FALSE; > > + > > + if (!rtx_equal_p (if_info->x, arg0)) > > + return FALSE; > > + > > + start_sequence (); > > + > > + target = noce_emit_condzero(if_info, arg1, op != AND ? true : false); > > + > > + if (target) > > + { > > + rtx op1 = if_info->x; > > + > > + if (op == AND) > > + { > > + /* Emit "tmp = x & val;" followed by "tmp |= !cond ? x : 0;" */ > > + op1 = expand_simple_binop (GET_MODE (if_info->x), AND, op1, > > + arg1, NULL_RTX, 0, OPTAB_WIDEN); > > + op = IOR; > > + } > > + > > + if (op1) > > + target = expand_simple_binop (GET_MODE (if_info->x), op, op1, > > + target, if_info->x, 0, OPTAB_WIDEN); > > + } > > + > > + if (target) > > + { > > + if (target != if_info->x) > > + noce_emit_move_insn (if_info->x, target); > > + > > + seq = end_ifcvt_sequence (if_info); > > + if (!seq || !targetm.noce_conversion_profitable_p (seq, if_info)) > > + return FALSE; > > + > > + emit_insn_before_setloc(seq, if_info->jump, > > + INSN_LOCATION(if_info->insn_a)); > > + if_info->transform_name = "noce_try_condzero_arith"; > > + > > + return TRUE; > > + } > > + > > + end_sequence (); > > + > > + return FALSE; > > +} > > + > > /* Convert "if (test) x = 0;" to "x &= -(test == 0);" */ > > > > static int > > @@ -3967,8 +4177,12 @@ noce_process_if_block (struct noce_if_info *if_info) > > { > > if (noce_try_addcc (if_info)) > > goto success; > > + if (noce_try_condzero (if_info)) > > + goto success; > > if (noce_try_store_flag_mask (if_info)) > > goto success; > > + if (noce_try_condzero_arith (if_info)) > > + goto success; > > if (HAVE_conditional_move > > && noce_try_cmove_arith (if_info)) > > goto success; > > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c > > new file mode 100644 > > index 00000000000..9b26cdf0513 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c > > @@ -0,0 +1,16 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ > > + > > +long and1(long a, long b, long c, long d) > > +{ > > + if (c < d) > > + a &= b; > > + > > + return a; > > +} > > + > > +/* { dg-final { scan-assembler-times "and\t" 1 } } */ > > +/* { dg-final { scan-assembler-times "slt" 1 } } */ > > +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ > > +/* { dg-final { scan-assembler-times "or\t" 1 } } */ > > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c > > new file mode 100644 > > index 00000000000..66d2ec10211 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c > > @@ -0,0 +1,15 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ > > + > > +int and2(int a, int b, long c) > > +{ > > + if (c) > > + a &= b; > > + > > + return a; > > +} > > + > > +/* { dg-final { scan-assembler-times "and\t" 1 } } */ > > +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ > > +/* { dg-final { scan-assembler-times "or\t" 1 } } */ > > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c > > new file mode 100644 > > index 00000000000..bc877d9e81b > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c > > @@ -0,0 +1,11 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" } } */ > > + > > +long > > +eq1 (long a, long b) > > +{ > > + return (a == 0) ? b : 0; > > +} > > + > > +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ > > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c > > new file mode 100644 > > index 00000000000..28317613ba8 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c > > @@ -0,0 +1,14 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" } } */ > > + > > +long > > +eq2 (long a, long b) > > +{ > > + if (a == 0) > > + return b; > > + > > + return 0; > > +} > > + > > +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ > > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c > > new file mode 100644 > > index 00000000000..db7498801f9 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c > > @@ -0,0 +1,16 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ > > + > > +long long sink (long long); > > + > > +long long lt3 (long long a, long long b) > > +{ > > + if (a < b) > > + b = 0; > > + > > + return sink(b); > > +} > > + > > +/* { dg-final { scan-assembler-times "vt.maskcn\" 1 } } */ > > +/* { dg-final { scan-assembler-times "slt\t" 1 } } */ > > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c > > new file mode 100644 > > index 00000000000..eff1486828c > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c > > @@ -0,0 +1,11 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" } } */ > > + > > +long long ne1(long long a, long long b) > > +{ > > + return (a != 0) ? b : 0; > > +} > > + > > +/* { dg-final { scan-assembler-times "vt.maskc" 1 } } */ > > + > > diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c > > new file mode 100644 > > index 00000000000..43020790a22 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c > > @@ -0,0 +1,14 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ > > +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ > > + > > +long xor1(long crc, long poly) > > +{ > > + if (crc & 1) > > + crc ^= poly; > > + > > + return crc; > > +} > > + > > +/* { dg-final { scan-assembler-times "vt.maskc" 1 } } */ > > +/* { dg-final { scan-assembler-times "xor\t" 1 } } */ > > -- > > 2.34.1 > >
diff --git a/gcc/ifcvt.cc b/gcc/ifcvt.cc index eb8efb89a89..41c58876d05 100644 --- a/gcc/ifcvt.cc +++ b/gcc/ifcvt.cc @@ -97,6 +97,7 @@ static int find_if_case_2 (basic_block, edge, edge); static int dead_or_predicable (basic_block, basic_block, basic_block, edge, int); static void noce_emit_move_insn (rtx, rtx); +static rtx_insn *noce_emit_insn (rtx); static rtx_insn *block_has_only_trap (basic_block); static void need_cmov_or_rewire (basic_block, hash_set<rtx_insn *> *, hash_map<rtx_insn *, int> *); @@ -787,6 +788,9 @@ static rtx noce_get_alt_condition (struct noce_if_info *, rtx, rtx_insn **); static int noce_try_minmax (struct noce_if_info *); static int noce_try_abs (struct noce_if_info *); static int noce_try_sign_mask (struct noce_if_info *); +static rtx noce_emit_condzero (struct noce_if_info *, rtx, bool = false); +static int noce_try_condzero (struct noce_if_info *); +static int noce_try_condzero_arith (struct noce_if_info *); /* Return the comparison code for reversed condition for IF_INFO, or UNKNOWN if reversing the condition is not possible. */ @@ -1664,6 +1668,212 @@ noce_try_addcc (struct noce_if_info *if_info) return FALSE; } +/* Helper to noce_try_condzero: cond ? a : 0. */ +static rtx +noce_emit_condzero (struct noce_if_info *if_info, rtx a, bool reverse) +{ + /* The canonical form for a conditional-zero-or-value is: + (set (match_operand 0 "register_operand" "=r") + (and (neg (eq_or_ne (match_operand 1 "register_operand" "r") + (const_int 0))) + (match_operand 2 "register_operand" "r"))) + */ + + machine_mode opmode = GET_MODE (if_info->x); + enum rtx_code code = GET_CODE (if_info->cond); + rtx cond; + rtx op_a = XEXP (if_info->cond, 0); + rtx op_b = XEXP (if_info->cond, 1); + + /* If it is not a EQ/NE comparison against const0_rtx, canonicalize + by first synthesizing a truth-value and then building a NE + condition around it. */ + if ((code != EQ && code != NE) || XEXP (if_info->cond, 1) != const0_rtx) + { + rtx tmp = gen_reg_rtx (opmode); + + start_sequence (); + cond = gen_rtx_fmt_ee (code, opmode, op_a, op_b); + if (!noce_emit_insn (gen_rtx_SET (tmp, cond))) + { + end_sequence (); + + /* If we can't emit this pattern, try to reverse it and + invert the polarity of the second test. */ + start_sequence (); + cond = gen_rtx_fmt_ee (reverse_condition (code), opmode, op_a, op_b); + if (!noce_emit_insn (gen_rtx_SET (tmp, cond))) { + end_sequence (); + return NULL_RTX; + } + + /* We have recovered by reversing the first comparison, + so we need change the second one around as well... */ + reverse = !reverse; + } + rtx_insn *seq = get_insns (); + end_sequence (); + emit_insn (seq); + + /* Set up the second comparison that will be embedded in the + canonical conditional-zero-or-value RTX. */ + code = NE; + op_a = tmp; + op_b = const0_rtx; + } + + cond = gen_rtx_fmt_ee (reverse ? reverse_condition (code) : code, + opmode, op_a, op_b); + + /* Build (and (neg (eq_or_ne ... const0_rtx)) (reg <a>)) */ + rtx target = gen_reg_rtx (opmode); + rtx czero = gen_rtx_AND (opmode, gen_rtx_NEG (opmode, cond), a); + noce_emit_move_insn (target, czero); + + return target; +} + +/* Use a conditional-zero instruction for "if (test) x = 0;", if available. */ +static int +noce_try_condzero (struct noce_if_info *if_info) +{ + rtx target; + rtx_insn *seq; + int reversep = 0; + rtx orig_b = NULL_RTX; + rtx cond = if_info->cond; + enum rtx_code code = GET_CODE (cond); + rtx cond_arg0 = XEXP (cond, 0); + rtx cond_arg1 = XEXP (cond, 1); + + if (!noce_simple_bbs (if_info)) + return FALSE; + + /* We may encounter the form "(a != 0) ? a : b", which can be + simplified to "a | ((a != 0) ? 0 : b)". */ + if (code == NE && cond_arg1 == const0_rtx && + REG_P (if_info->b) && rtx_equal_p (if_info->b, cond_arg0)) + { + orig_b = if_info->b; + if_info->b = const0_rtx; + } + + /* We may encounter the form "(a != 0) ? b : a", which can be + simplied to "(a != 0) ? b : 0". */ + if (code == EQ && cond_arg1 == const0_rtx && + REG_P (if_info->b) && rtx_equal_p (if_info->b, cond_arg0)) + { + /* We know that cond_arg0 is const_0, if the THEN branch is + taken... so if it is the same as if_info->b (yes, things are + backwards!), we can rewrite it with that knowledge. */ + if_info->b = const0_rtx; + } + + start_sequence (); + + if ((if_info->a == const0_rtx + && (REG_P (if_info->b) || rtx_equal_p (if_info->b, if_info->x))) + || ((reversep = (noce_reversed_cond_code (if_info) != UNKNOWN)) + && if_info->b == const0_rtx + && (REG_P (if_info->a) || rtx_equal_p (if_info->a, if_info->x)))) + { + target = noce_emit_condzero(if_info, + reversep ? if_info->a : if_info->b, + reversep); + + if (orig_b && target) + target = expand_simple_binop (GET_MODE (if_info->x), IOR, orig_b, + target, if_info->x, 0, OPTAB_WIDEN); + + if (target) + { + if (target != if_info->x) + noce_emit_move_insn (if_info->x, target); + + seq = end_ifcvt_sequence (if_info); + if (!seq || !targetm.noce_conversion_profitable_p (seq, if_info)) + return FALSE; + + emit_insn_before_setloc (seq, if_info->jump, + INSN_LOCATION (if_info->insn_a)); + if_info->transform_name = "noce_try_condzero"; + + return TRUE; + } + } + + end_sequence (); + + return FALSE; +} + +/* Convert "if (test) x op= a;" to a branchless sequence using the + canonical form for a conditional-zero. */ +static int +noce_try_condzero_arith (struct noce_if_info *if_info) +{ + rtx target; + rtx_insn *seq; + rtx_code op = GET_CODE (if_info->a); + const rtx arg0 = XEXP (if_info->a, 0); + const rtx arg1 = XEXP (if_info->a, 1); + + if (!noce_simple_bbs (if_info)) + return FALSE; + + /* Check for no else condition. */ + if (!rtx_equal_p (if_info->x, if_info->b)) + return FALSE; + + if (op != PLUS && op != MINUS && op != IOR && op != XOR && + op != ASHIFT && op != ASHIFTRT && op != LSHIFTRT && op != AND) + return FALSE; + + if (!rtx_equal_p (if_info->x, arg0)) + return FALSE; + + start_sequence (); + + target = noce_emit_condzero(if_info, arg1, op != AND ? true : false); + + if (target) + { + rtx op1 = if_info->x; + + if (op == AND) + { + /* Emit "tmp = x & val;" followed by "tmp |= !cond ? x : 0;" */ + op1 = expand_simple_binop (GET_MODE (if_info->x), AND, op1, + arg1, NULL_RTX, 0, OPTAB_WIDEN); + op = IOR; + } + + if (op1) + target = expand_simple_binop (GET_MODE (if_info->x), op, op1, + target, if_info->x, 0, OPTAB_WIDEN); + } + + if (target) + { + if (target != if_info->x) + noce_emit_move_insn (if_info->x, target); + + seq = end_ifcvt_sequence (if_info); + if (!seq || !targetm.noce_conversion_profitable_p (seq, if_info)) + return FALSE; + + emit_insn_before_setloc(seq, if_info->jump, + INSN_LOCATION(if_info->insn_a)); + if_info->transform_name = "noce_try_condzero_arith"; + + return TRUE; + } + + end_sequence (); + + return FALSE; +} + /* Convert "if (test) x = 0;" to "x &= -(test == 0);" */ static int @@ -3967,8 +4177,12 @@ noce_process_if_block (struct noce_if_info *if_info) { if (noce_try_addcc (if_info)) goto success; + if (noce_try_condzero (if_info)) + goto success; if (noce_try_store_flag_mask (if_info)) goto success; + if (noce_try_condzero_arith (if_info)) + goto success; if (HAVE_conditional_move && noce_try_cmove_arith (if_info)) goto success; diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c new file mode 100644 index 00000000000..9b26cdf0513 --- /dev/null +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ + +long and1(long a, long b, long c, long d) +{ + if (c < d) + a &= b; + + return a; +} + +/* { dg-final { scan-assembler-times "and\t" 1 } } */ +/* { dg-final { scan-assembler-times "slt" 1 } } */ +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ +/* { dg-final { scan-assembler-times "or\t" 1 } } */ diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c new file mode 100644 index 00000000000..66d2ec10211 --- /dev/null +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ + +int and2(int a, int b, long c) +{ + if (c) + a &= b; + + return a; +} + +/* { dg-final { scan-assembler-times "and\t" 1 } } */ +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ +/* { dg-final { scan-assembler-times "or\t" 1 } } */ diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c new file mode 100644 index 00000000000..bc877d9e81b --- /dev/null +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" } } */ + +long +eq1 (long a, long b) +{ + return (a == 0) ? b : 0; +} + +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c new file mode 100644 index 00000000000..28317613ba8 --- /dev/null +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" } } */ + +long +eq2 (long a, long b) +{ + if (a == 0) + return b; + + return 0; +} + +/* { dg-final { scan-assembler-times "vt.maskcn" 1 } } */ diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c new file mode 100644 index 00000000000..db7498801f9 --- /dev/null +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ + +long long sink (long long); + +long long lt3 (long long a, long long b) +{ + if (a < b) + b = 0; + + return sink(b); +} + +/* { dg-final { scan-assembler-times "vt.maskcn\" 1 } } */ +/* { dg-final { scan-assembler-times "slt\t" 1 } } */ diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c new file mode 100644 index 00000000000..eff1486828c --- /dev/null +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" } } */ + +long long ne1(long long a, long long b) +{ + return (a != 0) ? b : 0; +} + +/* { dg-final { scan-assembler-times "vt.maskc" 1 } } */ + diff --git a/gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c b/gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c new file mode 100644 index 00000000000..43020790a22 --- /dev/null +++ b/gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-march=rv64gc_xventanacondops -mabi=lp64" } */ +/* { dg-skip-if "" { *-*-* } { "-O0" "-Og" "-Os" "-Oz" } } */ + +long xor1(long crc, long poly) +{ + if (crc & 1) + crc ^= poly; + + return crc; +} + +/* { dg-final { scan-assembler-times "vt.maskc" 1 } } */ +/* { dg-final { scan-assembler-times "xor\t" 1 } } */
Some architectures, as it the case on RISC-V with the proposed ZiCondOps and the vendor-defined XVentanaCondOps, define a conditional-zero instruction that is equivalent to: - the positive form: rd = (rc != 0) ? rs : 0 - the negated form: rd = (rc == 0) ? rs : 0 While noce_try_store_flag_mask will somewhat work for this case, it will generate a number of atomic RTX that will misdirect the cost calculation and may be too long (i.e., 4 RTX and more) to successfully merge at combine-time. Instead, we add two new transforms that attempt to build up what we define as the canonical form of a conditional-zero expression: (set (match_operand 0 "register_operand" "=r") (and (neg (eq_or_ne (match_operand 1 "register_operand" "r") (const_int 0))) (match_operand 2 "register_operand" "r"))) Architectures that provide a conditional-zero are thus expected to define an instruction matching this pattern in their backend. Based on this, we support the following cases: - noce_try_condzero: a ? a : b a ? b : 0 (and then/else swapped) !a ? b : 0 (and then/else swapped) - noce_try_condzero_arith: conditional-plus, conditional-minus, conditional-and, conditional-or, conditional-xor, conditional-shift, conditional-and Given that this is hooked into the CE passes, it is less powerful than a tree-pass (e.g., it can not transform cases where an extension, such as for uint16_t operations is in either the then or else-branch together with the arithmetic) but already covers a good array of cases and triggers across SPEC CPU 2017. Adding transofmrations in a tree pass will be considered as a future improvement. gcc/ChangeLog: * ifcvt.cc (noce_emit_insn): Add prototype. (noce_emit_condzero): Helper for noce_try_condzero and noce_try_condzero_arith transforms. (noce_try_condzero): New transform. (noce_try_condzero_arith): New transform for conditional arithmetic that can be built up by exploiting that the conditional-zero instruction will inject 0, which acts as the neutral element for operations. (noce_process_if_block): Call noce_try_condzero and noce_try_condzero_arith. gcc/testsuite/ChangeLog: * gcc.target/riscv/xventanacondops-and-01.c: New test. * gcc.target/riscv/xventanacondops-and-02.c: New test. * gcc.target/riscv/xventanacondops-eq-01.c: New test. * gcc.target/riscv/xventanacondops-eq-02.c: New test. * gcc.target/riscv/xventanacondops-lt-01.c: New test. * gcc.target/riscv/xventanacondops-ne-01.c: New test. * gcc.target/riscv/xventanacondops-xor-01.c: New test. Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu> --- gcc/ifcvt.cc | 214 ++++++++++++++++++ .../gcc.target/riscv/xventanacondops-and-01.c | 16 ++ .../gcc.target/riscv/xventanacondops-and-02.c | 15 ++ .../gcc.target/riscv/xventanacondops-eq-01.c | 11 + .../gcc.target/riscv/xventanacondops-eq-02.c | 14 ++ .../gcc.target/riscv/xventanacondops-lt-01.c | 16 ++ .../gcc.target/riscv/xventanacondops-ne-01.c | 11 + .../gcc.target/riscv/xventanacondops-xor-01.c | 14 ++ 8 files changed, 311 insertions(+) create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-and-01.c create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-and-02.c create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-eq-01.c create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-eq-02.c create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-lt-01.c create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-ne-01.c create mode 100644 gcc/testsuite/gcc.target/riscv/xventanacondops-xor-01.c