On May 7, 2021 4:12:02 PM GMT+02:00, Christophe Lyon
<christophe.l...@linaro.org> wrote:
>On Wed, 5 May 2021 at 09:56, Richard Biener <rguent...@suse.de> wrote:
>>
>> This makes sure to follow SSA edges when folding eliminated stmts.
>> This reaps the same benefit as forwprop folding all stmts, not
>> waiting for one to produce copysign in the new testcase.
>>
>> Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
>>
>> 2021-05-04 Richard Biener <rguent...@suse.de>
>>
>> PR tree-optimization/79333
>> * tree-ssa-sccvn.c (eliminate_dom_walker::eliminate_stmt):
>> Fold stmt following SSA edges.
>>
>> * gcc.dg/tree-ssa/ssa-fre-94.c: New testcase.
>> * gcc.dg/graphite/fuse-1.c: Adjust.
>> * gcc.dg/pr43864-4.c: Likewise.
>> ---
>> gcc/testsuite/gcc.dg/graphite/fuse-1.c | 4 ++--
>> gcc/testsuite/gcc.dg/pr43864-4.c | 6 +++---
>> gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-94.c | 16 ++++++++++++++++
>> gcc/tree-ssa-sccvn.c | 2 +-
>> 4 files changed, 22 insertions(+), 6 deletions(-)
>> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-94.c
>>
>> diff --git a/gcc/testsuite/gcc.dg/graphite/fuse-1.c
>b/gcc/testsuite/gcc.dg/graphite/fuse-1.c
>> index 204d3b20703..527b6e5c415 100644
>> --- a/gcc/testsuite/gcc.dg/graphite/fuse-1.c
>> +++ b/gcc/testsuite/gcc.dg/graphite/fuse-1.c
>> @@ -1,6 +1,6 @@
>> /* Check that the two loops are fused and that we manage to fold the
>two xor
>> operations. */
>> -/* { dg-options "-O2 -floop-nest-optimize -fdump-tree-forwprop-all
>-fdump-tree-graphite-all" } */
>> +/* { dg-options "-O2 -floop-nest-optimize -fdump-tree-forwprop4
>-fdump-tree-graphite-all" } */
>>
>> /* Make sure we fuse the loops like this:
>> AST generated by isl:
>> @@ -12,7 +12,7 @@ for (int c0 = 0; c0 <= 99; c0 += 1) {
>> /* { dg-final { scan-tree-dump-times "AST generated by isl:.*for
>\\(int c0 = 0; c0 <= 99; c0 \\+= 1\\)
>\\{.*S_.*\\(c0\\);.*S_.*\\(c0\\);.*S_.*\\(c0\\);.*\\}" 1 "graphite" } }
>*/
>>
>> /* Check that after fusing the loops, the scalar computation is also
>fused. */
>> -/* { dg-final { scan-tree-dump-times "gimple_simplified
>to\[^\\n\]*\\^ 12" 1 "forwprop4" } } */
>> +/* { dg-final { scan-tree-dump-times " \\^ 12;" 2 "forwprop4" } } */
>>
>> #define MAX 100
>> int A[MAX];
>> diff --git a/gcc/testsuite/gcc.dg/pr43864-4.c
>b/gcc/testsuite/gcc.dg/pr43864-4.c
>> index 3c6cc50c5b8..8a25b0fd8ef 100644
>> --- a/gcc/testsuite/gcc.dg/pr43864-4.c
>> +++ b/gcc/testsuite/gcc.dg/pr43864-4.c
>> @@ -22,7 +22,7 @@ int f(int c, int b, int d)
>> return r - r2;
>> }
>>
>> -/* { dg-final { scan-tree-dump-times "if " 0 "pre"} } */
>> -/* { dg-final { scan-tree-dump-times "(?n)_.*\\+.*_" 1 "pre"} } */
>> -/* { dg-final { scan-tree-dump-times "(?n)_.*-.*_" 2 "pre"} } */
>> +/* During PRE elimination we should simplify this to return b * 2.
>*/
>> +/* { dg-final { scan-tree-dump-times "if " 0 "pre" } } */
>> +/* { dg-final { scan-tree-dump "_\[0-9\]+ = b_\[0-9\]+\\(D\\) \\*
>2;\[\\r\\n\]\[^\\r\\n\]*return _\[0-9\]+;" "pre" } } */
>> /* { dg-final { scan-tree-dump-not "Invalid sum" "pre"} } */
>> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-94.c
>b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-94.c
>> new file mode 100644
>> index 00000000000..92eebf636c6
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-94.c
>> @@ -0,0 +1,16 @@
>> +/* PR tree-optimization/79333 */
>> +/* { dg-do compile } */
>> +/* { dg-options "-O -ffinite-math-only -fdump-tree-fre1" } */
>> +
>> +extern __inline __attribute__ ((__always_inline__,__gnu_inline__))
>> +double __attribute__ ((__nothrow__ , __leaf__))
>> +fabs (double __x) { return __builtin_fabs (__x); }
>> +
>> +double f(float f)
>> +{
>> + double t1 = fabs(f);
>> + double t2 = f / t1;
>> + return t2;
>> +}
>> +
>> +/* { dg-final { scan-tree-dump "copysign" "fre1" } } */
>
>This new testcase fails on aarch64-elf / arm-eabi with newlib.
>
>Is that OK:
Yes, OK.
Thanks,
Richard.
>===========================
>diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-94.c
>b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-94.c
>index 92eebf636c6..99c737562bb 100644
>--- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-94.c
>+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-94.c
>@@ -1,5 +1,6 @@
> /* PR tree-optimization/79333 */
> /* { dg-do compile } */
>+/* { dg-require-effective-target c99_runtime } */
> /* { dg-options "-O -ffinite-math-only -fdump-tree-fre1" } */
>
> extern __inline __attribute__ ((__always_inline__,__gnu_inline__))
>===========================
>
>Thanks,
>
>Christophe
>
>
>
>
>> diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
>> index ca0974d72b8..e54a0c9065c 100644
>> --- a/gcc/tree-ssa-sccvn.c
>> +++ b/gcc/tree-ssa-sccvn.c
>> @@ -6362,7 +6362,7 @@ eliminate_dom_walker::eliminate_stmt
>(basic_block b, gimple_stmt_iterator *gsi)
>> recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1
>(stmt));
>> gimple_stmt_iterator prev = *gsi;
>> gsi_prev (&prev);
>> - if (fold_stmt (gsi))
>> + if (fold_stmt (gsi, follow_all_ssa_edges))
>> {
>> /* fold_stmt may have created new stmts inbetween
>> the previous stmt and the folded stmt. Mark
>> --
>> 2.26.2
