| Message ID | 20200103082331.GK10088@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | Fix x86 abs<mode>2 expander for ia32 (PR target/93110) | expand |
On Fri, Jan 3, 2020 at 9:23 AM Jakub Jelinek <jakub@redhat.com> wrote: > > Hi! > > The newly added absdi2 expander doesn't work well on ia32, because it > requires a xordi3 pattern, which is available even for !TARGET_64BIT, > but only if TARGET_STV && TARGET_SSE2. > > The following patch just uses expand_simple_binop which is able to handle > the splitting of it into two xorsi3 patterns if needed etc., plus is shorter > in the expander. Also, there is no need to build a DImode shift amount and > then convert_modes it. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, on the > testcase we now get identical code to what GCC 9 emitted in all of -m32 > -mno-stv -mno-sse, -m32 -msse2 -mstv and -m64 modes, ok for trunk? > > 2020-01-03 Jakub Jelinek <jakub@redhat.com> > > PR target/93110 > * config/i386/i386.md (abs<mode>2): Use expand_simple_binop instead of > emitting ASHIFTRT, XOR and MINUS by hand. Use gen_int_mode with QImode > instead of gen_int_shift_amount + convert_modes. > > * gcc.dg/torture/pr93110.c: New test. OK. Thanks, Uros. > --- gcc/config/i386/i386.md.jj 2020-01-01 12:16:10.071276261 +0100 > +++ gcc/config/i386/i386.md 2020-01-02 10:47:26.638399487 +0100 > @@ -9711,30 +9711,16 @@ (define_expand "abs<mode>2" > > /* Generate rtx abs using abs (x) = (((signed) x >> (W-1)) ^ x) - > ((signed) x >> (W-1)) */ > - rtx shift_amount = gen_int_shift_amount (mode, > - GET_MODE_PRECISION (mode) > - - 1); > - shift_amount = convert_modes (E_QImode, GET_MODE (shift_amount), > - shift_amount, 1); > - rtx shift_dst = gen_reg_rtx (mode); > - rtx shift_op = gen_rtx_SET (shift_dst, > - gen_rtx_fmt_ee (ASHIFTRT, mode, > - operands[1], shift_amount)); > - rtx clobber = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (CCmode, > - FLAGS_REG)); > - emit_insn (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, shift_op, > - clobber))); > - > - rtx xor_op = gen_rtx_SET (operands[0], > - gen_rtx_fmt_ee (XOR, mode, shift_dst, > - operands[1])); > - emit_insn (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, xor_op, clobber))); > - > - rtx minus_op = gen_rtx_SET (operands[0], > - gen_rtx_fmt_ee (MINUS, mode, > - operands[0], shift_dst)); > - emit_insn (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, minus_op, > - clobber))); > + rtx shift_amount = gen_int_mode (GET_MODE_PRECISION (mode) - 1, QImode); > + rtx shift_dst = expand_simple_binop (mode, ASHIFTRT, operands[1], > + shift_amount, NULL_RTX, > + 0, OPTAB_DIRECT); > + rtx xor_dst = expand_simple_binop (mode, XOR, shift_dst, operands[1], > + operands[0], 0, OPTAB_DIRECT); > + rtx minus_dst = expand_simple_binop (mode, MINUS, xor_dst, shift_dst, > + operands[0], 0, OPTAB_DIRECT); > + if (!rtx_equal_p (minus_dst, operands[0])) > + emit_move_insn (operands[0], minus_dst); > DONE; > }) > > --- gcc/testsuite/gcc.dg/torture/pr93110.c.jj 2020-01-02 10:50:10.335895988 +0100 > +++ gcc/testsuite/gcc.dg/torture/pr93110.c 2020-01-02 10:49:54.248142020 +0100 > @@ -0,0 +1,9 @@ > +/* PR target/93110 */ > +/* { dg-do compile } */ > +/* { dg-additional-options "-mtune=core2 -mno-stv" { target { i?86-*-* x86_64-*-* } } } */ > + > +long long > +foo (long long a) > +{ > + return a > 0 ? a : -a; > +} > > Jakub >
--- gcc/config/i386/i386.md.jj 2020-01-01 12:16:10.071276261 +0100 +++ gcc/config/i386/i386.md 2020-01-02 10:47:26.638399487 +0100 @@ -9711,30 +9711,16 @@ (define_expand "abs<mode>2" /* Generate rtx abs using abs (x) = (((signed) x >> (W-1)) ^ x) - ((signed) x >> (W-1)) */ - rtx shift_amount = gen_int_shift_amount (mode, - GET_MODE_PRECISION (mode) - - 1); - shift_amount = convert_modes (E_QImode, GET_MODE (shift_amount), - shift_amount, 1); - rtx shift_dst = gen_reg_rtx (mode); - rtx shift_op = gen_rtx_SET (shift_dst, - gen_rtx_fmt_ee (ASHIFTRT, mode, - operands[1], shift_amount)); - rtx clobber = gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (CCmode, - FLAGS_REG)); - emit_insn (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, shift_op, - clobber))); - - rtx xor_op = gen_rtx_SET (operands[0], - gen_rtx_fmt_ee (XOR, mode, shift_dst, - operands[1])); - emit_insn (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, xor_op, clobber))); - - rtx minus_op = gen_rtx_SET (operands[0], - gen_rtx_fmt_ee (MINUS, mode, - operands[0], shift_dst)); - emit_insn (gen_rtx_PARALLEL (VOIDmode, gen_rtvec (2, minus_op, - clobber))); + rtx shift_amount = gen_int_mode (GET_MODE_PRECISION (mode) - 1, QImode); + rtx shift_dst = expand_simple_binop (mode, ASHIFTRT, operands[1], + shift_amount, NULL_RTX, + 0, OPTAB_DIRECT); + rtx xor_dst = expand_simple_binop (mode, XOR, shift_dst, operands[1], + operands[0], 0, OPTAB_DIRECT); + rtx minus_dst = expand_simple_binop (mode, MINUS, xor_dst, shift_dst, + operands[0], 0, OPTAB_DIRECT); + if (!rtx_equal_p (minus_dst, operands[0])) + emit_move_insn (operands[0], minus_dst); DONE; }) --- gcc/testsuite/gcc.dg/torture/pr93110.c.jj 2020-01-02 10:50:10.335895988 +0100 +++ gcc/testsuite/gcc.dg/torture/pr93110.c 2020-01-02 10:49:54.248142020 +0100 @@ -0,0 +1,9 @@ +/* PR target/93110 */ +/* { dg-do compile } */ +/* { dg-additional-options "-mtune=core2 -mno-stv" { target { i?86-*-* x86_64-*-* } } } */ + +long long +foo (long long a) +{ + return a > 0 ? a : -a; +}