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* [gcc r14-4729] Fix expansion of `(a & 2) != 1`
@ 2023-10-18 22:35 Andrew Pinski
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From: Andrew Pinski @ 2023-10-18 22:35 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:b20dbddcc41120144e700c4e3ef1ec396b1c56ab
commit r14-4729-gb20dbddcc41120144e700c4e3ef1ec396b1c56ab
Author: Andrew Pinski <pinskia@gmail.com>
Date: Wed Oct 18 10:26:07 2023 -0700
Fix expansion of `(a & 2) != 1`
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.
Diff:
---
gcc/expr.cc | 9 +++++----
gcc/testsuite/gcc.c-torture/execute/pr111863-1.c | 16 ++++++++++++++++
2 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/gcc/expr.cc b/gcc/expr.cc
index 8aed3fc6cbe9..763bd82c59f2 100644
--- a/gcc/expr.cc
+++ b/gcc/expr.cc
@@ -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);
}
}
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr111863-1.c b/gcc/testsuite/gcc.c-torture/execute/pr111863-1.c
new file mode 100644
index 000000000000..4e27fe631b21
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr111863-1.c
@@ -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;
+}
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