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tree-inline: Fix a -fcompare-debug issue in the inliner [PR94167]

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The following testcase fails with -fcompare-debug.  The problem is that
bar is marked as address_taken only with -g and not without.
I've tracked it down to insert_init_stmt calling gimple_regimplify_operands
even on DEBUG_STMTs.  That function will just insert normal stmts before
the DEBUG_STMT if the DEBUG_STMT operand isn't gimple val or invariant.
While DCE will turn those statements into debug temporaries, it can cause
differences in SSA_NAMEs and more importantly, the ipa references are
generated from those before the DCE happens.
On the testcase, the DEBUG_STMT value is (int)bar.

We could generate DEBUG_STMTs with debug temporaries instead, but I fail to
see the reason to do that, DEBUG_STMTs allow other expressions and all we
want to ensure is that the expressions aren't too large (arbitrarily
complex), but during inlining/function versioning I don't see why something
would queue a DEBUG_STMT with arbitrarily complex expressions in there.

2020-03-16  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/94166
	* tree-ssa-reassoc.c (sort_by_mach_mode): Use SSA_NAME_VERSION
	as secondary comparison key.

	* gcc.dg/pr94166.c: New test.
This commit is contained in:
Jakub Jelinek 2020-03-16 09:02:21 +01:00
parent e4e9a59105
commit 5ba25b2ef1
4 changed files with 40 additions and 2 deletions
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6
gcc/ChangeLog
View File

@ -1,3 +1,9 @@
2020-03-16 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/94166
* tree-ssa-reassoc.c (sort_by_mach_mode): Use SSA_NAME_VERSION
as secondary comparison key.
2020-03-16 Bin Cheng <bin.cheng@linux.alibaba.com>
PR tree-optimization/94125

5
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,8 @@
2020-03-16 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/94166
* gcc.dg/pr94166.c: New test.
2020-03-16 Bin Cheng <bin.cheng@linux.alibaba.com>
PR tree-optimization/94125

24
gcc/testsuite/gcc.dg/pr94166.c Normal file
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@ -0,0 +1,24 @@
/* PR tree-optimization/94166 */
/* { dg-do compile } */
/* { dg-options "-O2 -fcompare-debug" } */
typedef int __m128i __attribute__((__may_alias__, __vector_size__(4 * sizeof (int))));
unsigned int b[512];
void
foo (unsigned int *x, __m128i *y)
{
#define A(n) __m128i v##n = y[n];
#define B(n) A(n##0) A(n##1) A(n##2) A(n##3) A(n##4) A(n##5) A(n##6) A(n##7) \
A(n##8) A(n##9) A(n##a) A(n##b) A(n##c) A(n##d) A(n##e) A(n##f)
#define C(n) B(n##0) B(n##1) B(n##2) B(n##3) B(n##4) B(n##5) B(n##6) B(n##7)
C(0x)
#undef A
#define A(n) *(__m128i *) &b[4 * n] = v##n;
C(0x)
#undef A
#define A(n) + b[4 * n] + b[4 * n + 1] + b[4 * n + 2] + b[4 * n + 3]
*x = *x
C(0x)
;
}

7
gcc/tree-ssa-reassoc.c
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@ -1793,8 +1793,11 @@ sort_by_mach_mode (const void *p_i, const void *p_j)
return 1;
else if (mode1 < mode2)
return -1;
else
return 0;
if (SSA_NAME_VERSION (tr1) < SSA_NAME_VERSION (tr2))
return -1;
else if (SSA_NAME_VERSION (tr1) > SSA_NAME_VERSION (tr2))
return 1;
return 0;
}
/* Cleanup hash map for VECTOR information. */