re PR tree-optimization/86034 (wrong code for bit-field manipulation at -Os)

PR tree-optimization/86034
	* gimple-ssa-store-merging.c (output_merged_store): Convert the RHS to
	the unsigned bitfield type in a bit insertion sequence if it does not
	have a larger precision than the bitfield size.
	(process_store): Also bypass widening conversions for BIT_INSERT_EXPR.

From-SVN: r261128
This commit is contained in:
Eric Botcazou 2018-06-03 11:51:10 +00:00 committed by Eric Botcazou
parent 5b9a3332c2
commit c14add82fa
4 changed files with 54 additions and 4 deletions

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@ -1,3 +1,11 @@
2018-06-03 Eric Botcazou <ebotcazou@adacore.com>
PR tree-optimization/86034
* gimple-ssa-store-merging.c (output_merged_store): Convert the RHS to
the unsigned bitfield type in a bit insertion sequence if it does not
have a larger precision than the bitfield size.
(process_store): Also bypass widening conversions for BIT_INSERT_EXPR.
2018-06-03 Kito Cheng <kito.cheng@gmail.com>
* config/nds32/nds32-peephole2.md: Add new patterns for code size.

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@ -3778,7 +3778,14 @@ imm_store_chain_info::output_merged_store (merged_store_group *group)
const HOST_WIDE_INT end_gap
= (try_bitpos + try_size) - (info->bitpos + info->bitsize);
tree tem = info->ops[0].val;
if ((BYTES_BIG_ENDIAN ? start_gap : end_gap) > 0)
if (TYPE_PRECISION (TREE_TYPE (tem)) <= info->bitsize)
{
tree bitfield_type
= build_nonstandard_integer_type (info->bitsize,
UNSIGNED);
tem = gimple_convert (&seq, loc, bitfield_type, tem);
}
else if ((BYTES_BIG_ENDIAN ? start_gap : end_gap) > 0)
{
const unsigned HOST_WIDE_INT imask
= (HOST_WIDE_INT_1U << info->bitsize) - 1;
@ -4270,13 +4277,12 @@ pass_store_merging::process_store (gimple *stmt)
|| !multiple_p (bitpos, BITS_PER_UNIT))
&& const_bitsize <= 64)
{
/* Bypass a truncating conversion to the bit-field type. */
/* Bypass a conversion to the bit-field type. */
if (is_gimple_assign (def_stmt) && CONVERT_EXPR_CODE_P (rhs_code))
{
tree rhs1 = gimple_assign_rhs1 (def_stmt);
if (TREE_CODE (rhs1) == SSA_NAME
&& INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
&& const_bitsize <= TYPE_PRECISION (TREE_TYPE (rhs1)))
&& INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
rhs = rhs1;
}
rhs_code = BIT_INSERT_EXPR;

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@ -1,3 +1,7 @@
2018-06-03 Eric Botcazou <ebotcazou@adacore.com>
* gcc.dg/torture/pr86034.c: New test.
2018-06-03 Paul Thomas <pault@gcc.gnu.org>
PR fortran/36497

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@ -0,0 +1,32 @@
/* PR tree-optimization/86034 */
/* Testcase by Zhendong Su <su@cs.ucdavis.edu> */
/* { dg-do run } */
struct A
{
int b;
int c:24;
int d:10;
int e;
} f;
int g;
void h ()
{
struct A i = { 0, 0, -1, 0 };
L:
f = i;
i.d = 0;
if (g < 0)
goto L;
}
int main (void)
{
h ();
if (f.e != 0)
__builtin_abort ();
return 0;
}