Message ID | 20191010221636.22199-1-jimw@sifive.com |
---|---|
State | New |
Headers | show |
Series | [v2] Extend subst to simplify CONST_INT inside SIGN_EXTEND. | expand |
Hi! On Thu, Oct 10, 2019 at 03:16:36PM -0700, Jim Wilson wrote: > This addresses PR 91860 which has four testcases triggering internal errors. > The problem here is that in combine when handling debug insns, we are trying > to substitute > (sign_extend:DI (const_int 8160 [0x1fe0])) > as the value for > (reg:DI 78 [ _9 ]) > in the debug insn > (debug_insn 29 28 30 2 (var_location:QI d (subreg:QI (reg:DI 78 [ _9 ]) 0)) "tmp4.c":11:5 -1 > (nil)) > This eventually triggers an abort because 8160 is not a sign-extended > QImode value. > > We should avoid creating the invalid RTL in the first place. It is *normal* for combine to create invalid RTL. It first creates it, and it checks if it is valid later. However: > In subst there > is already code to avoid putting a CONST_INT inside a ZERO_EXTEND. This > needs to be extended to also handle a SIGN_EXTEND the same way. That works, sure. Approved for trunk. Thanks! Segher
diff --git a/gcc/combine.c b/gcc/combine.c index d295a81abf9..92e4e5e6898 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -5680,6 +5680,7 @@ subst (rtx x, rtx from, rtx to, int in_dest, int in_cond, int unique_copy) } else if (CONST_SCALAR_INT_P (new_rtx) && (GET_CODE (x) == ZERO_EXTEND + || GET_CODE (x) == SIGN_EXTEND || GET_CODE (x) == FLOAT || GET_CODE (x) == UNSIGNED_FLOAT)) { diff --git a/gcc/testsuite/gcc.dg/pr91860-1.c b/gcc/testsuite/gcc.dg/pr91860-1.c new file mode 100644 index 00000000000..e715040e33d --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr91860-1.c @@ -0,0 +1,18 @@ +/* { dg-do compile } */ +/* { dg-options "-Og -fipa-cp -g --param=max-combine-insns=3" } */ + +char a; +int b; + +static void +bar (short d) +{ + d <<= __builtin_sub_overflow (0, d, &a); + b = __builtin_bswap16 (~d); +} + +void +foo (void) +{ + bar (21043); +} diff --git a/gcc/testsuite/gcc.dg/pr91860-2.c b/gcc/testsuite/gcc.dg/pr91860-2.c new file mode 100644 index 00000000000..7b44e648ca6 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr91860-2.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-Og -fexpensive-optimizations -fno-tree-fre -g --param=max-combine-insns=4" } */ + +unsigned a, b, c; +void +foo (void) +{ + unsigned short e; + __builtin_mul_overflow (0, b, &a); + __builtin_sub_overflow (59347, 9, &e); + e <<= a & 5; + c = e; +} diff --git a/gcc/testsuite/gcc.dg/pr91860-3.c b/gcc/testsuite/gcc.dg/pr91860-3.c new file mode 100644 index 00000000000..2b488cc9048 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr91860-3.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-Og -g2 --param=max-combine-insns=3" } */ + +int a, b; + +void +foo (void) +{ + unsigned short d = 46067; + int e = e; + d <<= __builtin_mul_overflow (~0, e, &a); + d |= -68719476735; + b = d; +} + diff --git a/gcc/testsuite/gcc.dg/pr91860-4.c b/gcc/testsuite/gcc.dg/pr91860-4.c new file mode 100644 index 00000000000..36f2bd55c64 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr91860-4.c @@ -0,0 +1,24 @@ +/* { dg-do compile } */ +/* { dg-require-effective-target int128 } */ +/* { dg-options "-O2 -g" } */ + +typedef unsigned char u8; +typedef unsigned int u32; +typedef unsigned __int128 u128; + +u32 b, c; + +static inline +u128 bar (u8 d, u128 e) +{ + __builtin_memset (11 + (char *) &e, b, 1); + d <<= e & 7; + d = d | d > 0; + return d + e; +} + +void +foo (void) +{ + c = bar (~0, 5); +}