FreeChainXenon/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

middle-end/106053 - fold_sign_changed_comparison and large bools

Browse source 
The following fixes a latent issue in the match.pd variant of
fold_sign_changed_comparison which replaces an unsigned integer
comparison with a signed boolean comparison of the same precision
despite the fact that we treat BOOLEAN_TYPEs as only having two
valid values.

2022-06-28  Richard Biener  <rguenther@suse.de>

	PR middle-end/106053
	* match.pd ((T)a == (T)b): Avoid folding away sign
	changes in a comparison if we'd truncate to a boolean.

	* gcc.target/i386/pr106053.c: New testcase.
This commit is contained in:
Richard Biener 2022-06-28 10:50:34 +02:00
parent 6835baee71
commit a3ca1fc5f4
2 changed files with 43 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
gcc/match.pd
View file

@ -5542,7 +5542,12 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
&& (TYPE_UNSIGNED (TREE_TYPE (@00)) == TYPE_UNSIGNED (TREE_TYPE (@0))
|| cmp == NE_EXPR
|| cmp == EQ_EXPR)
&& !POINTER_TYPE_P (TREE_TYPE (@00)))
&& !POINTER_TYPE_P (TREE_TYPE (@00))
/* (int)bool:32 != (int)uint is not the same as
bool:32 != (bool:32)uint since boolean types only have two valid
values independent of their precision. */
&& (TREE_CODE (TREE_TYPE (@00)) != BOOLEAN_TYPE
|| TREE_CODE (TREE_TYPE (@10)) == BOOLEAN_TYPE))
/* ??? The special-casing of INTEGER_CST conversion was in the original
code and here to avoid a spurious overflow flag on the resulting
constant which fold_convert produces. */

37
gcc/testsuite/gcc.target/i386/pr106053.c Normal file
View file

@ -0,0 +1,37 @@
/* { dg-do run { target lp64 } } */
/* { dg-options "-O -fno-tree-fre -w -mno-avx" } */
typedef unsigned __attribute__((__vector_size__ (32))) v256u8;
typedef unsigned __attribute__((__vector_size__ (64))) v512u8;
typedef unsigned short u16;
typedef unsigned int u32;
typedef unsigned long long u64;
typedef unsigned long __attribute__((__vector_size__ (64))) v512u64;
typedef unsigned __int128 __attribute__((__vector_size__ (32))) v256u128;
unsigned u;
v512u64 foo0_v512u64_0;
static inline v256u8
foo (u32 u32_0, u64 u64_0, v256u128 v256u128_0)
{
int o = __builtin_add_overflow_p (u64_0, 0, 0);
v512u64 v512u64_1 =
foo0_v512u64_0 & (u32) __builtin_sub_overflow_p (0, o, 0);
u64_0 |= u;
v256u128 v256u128_2 = u64_0 < v256u128_0;
v256u128 v256u128_3 = -v256u128_2 == u64_0 * u32_0;
v256u8 v256u8_r = ((union {
v512u8 a; v256u8 b[2];
}) (v512u8) v512u64_1).b[0] + (v256u8) v256u128_3;
return v256u8_r;
}
int
main (void)
{
v256u8 x = foo (3095179400, 23725760132, (v256u128) { 2, 2 });
for (unsigned i = 0; i < sizeof (x) / sizeof (x[0]); i++)
if (x[i])
__builtin_abort ();
return 0;
}