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Fix PR tree-optimization/86066
- From: Eric Botcazou <ebotcazou at adacore dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Wed, 06 Jun 2018 15:13:59 +0200
- Subject: Fix PR tree-optimization/86066
process_store was wrongly bypassing a BIT_NOT_EXPR if there was a NOP_EXPR
right after it in the SSA chain.
Tested on x86-64/Linux, applied on the mainline as obvious.
2018-06-06 Eric Botcazou <ebotcazou@adacore.com>
PR tree-optimization/86066
* gimple-ssa-store-merging.c (process_store): Do not bypass BIT_NOT_EXPR
for BIT_INSERT_EXPR stores.
2018-06-06 Eric Botcazou <ebotcazou@adacore.com>
* gcc.dg/torture/pr86066.c: New test.
--
Eric Botcazou
Index: gimple-ssa-store-merging.c
===================================================================
--- gimple-ssa-store-merging.c (revision 261173)
+++ gimple-ssa-store-merging.c (working copy)
@@ -4333,7 +4333,9 @@ pass_store_merging::process_store (gimpl
&& const_bitsize <= 64)
{
/* Bypass a conversion to the bit-field type. */
- if (is_gimple_assign (def_stmt) && CONVERT_EXPR_CODE_P (rhs_code))
+ if (!bit_not_p
+ && is_gimple_assign (def_stmt)
+ && CONVERT_EXPR_CODE_P (rhs_code))
{
tree rhs1 = gimple_assign_rhs1 (def_stmt);
if (TREE_CODE (rhs1) == SSA_NAME
@@ -4341,6 +4343,7 @@ pass_store_merging::process_store (gimpl
rhs = rhs1;
}
rhs_code = BIT_INSERT_EXPR;
+ bit_not_p = false;
ops[0].val = rhs;
ops[0].base_addr = NULL_TREE;
ops[1].base_addr = NULL_TREE;
/* PR tree-optimization/86066 */
/* Testcase by Zhendong Su <Zhendong Su> */
struct A
{
int b:2;
int c:2;
unsigned d:8;
};
int main ()
{
struct A t = { 0, 0, 2 };
L:
t.d = ~(~(~0 % t.d) % 2);
if (!t.d)
goto L;
return 0;
}