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Fix expansion of (a & 2) != 1

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I had a thinko in r14-1600-ge60593f3881c72a96a3fa4844d73e8a2cd14f670
where we would remove the `& CST` part if we ended up not calling
expand_single_bit_test.
This fixes the problem by introducing a new variable that will be used
for calling expand_single_bit_test.
As afar as I know this can only show up when disabling optimization
passes as this above form would have been optimized away.

Committed as obvious after a bootstrap/test on x86_64-linux-gnu.

	PR middle-end/111863

gcc/ChangeLog:

	* expr.cc (do_store_flag): Don't over write arg0
	when stripping off `& POW2`.

gcc/testsuite/ChangeLog:

	* gcc.c-torture/execute/pr111863-1.c: New test.
This commit is contained in:
Andrew Pinski 2023-10-18 10:26:07 -07:00
parent 879c91fccc
commit b20dbddcc4
2 changed files with 21 additions and 4 deletions
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9
gcc/expr.cc
View file

@ -13206,14 +13206,15 @@ do_store_flag (sepops ops, rtx target, machine_mode mode)
|| integer_pow2p (arg1))
&& (TYPE_PRECISION (ops->type) != 1 || TYPE_UNSIGNED (ops->type)))
{
wide_int nz = tree_nonzero_bits (arg0);
gimple *srcstmt = get_def_for_expr (arg0, BIT_AND_EXPR);
tree narg0 = arg0;
wide_int nz = tree_nonzero_bits (narg0);
gimple *srcstmt = get_def_for_expr (narg0, BIT_AND_EXPR);
/* If the defining statement was (x & POW2), then use that instead of
the non-zero bits. */
if (srcstmt && integer_pow2p (gimple_assign_rhs2 (srcstmt)))
{
nz = wi::to_wide (gimple_assign_rhs2 (srcstmt));
arg0 = gimple_assign_rhs1 (srcstmt);
narg0 = gimple_assign_rhs1 (srcstmt);
}
if (wi::popcount (nz) == 1
@ -13227,7 +13228,7 @@ do_store_flag (sepops ops, rtx target, machine_mode mode)
type = lang_hooks.types.type_for_mode (mode, unsignedp);
return expand_single_bit_test (loc, tcode,
arg0,
narg0,
bitnum, type, target, mode);
}
}

16
gcc/testsuite/gcc.c-torture/execute/pr111863-1.c Normal file
View file

@ -0,0 +1,16 @@
/* { dg-options " -fno-tree-ccp -fno-tree-dominator-opts -fno-tree-vrp" } */
__attribute__((noipa))
int f(int a)
{
a &= 2;
return a != 1;
}
int main(void)
{
int t = f(1);
if (!t)
__builtin_abort();
__builtin_printf("%d\n",t);
return 0;
}