diff options
| author | Andrew Pinski <apinski@marvell.com> | 2023-09-21 03:05:17 +0000 |
|---|---|---|
| committer | Andrew Pinski <pinskia@gmail.com> | 2023-09-26 14:55:01 +0000 |
| commit | 68fa82e2d8f868a233103102dff2449a416bc566 (patch) | |
| tree | e2922a8de96fb489890afba24d1861d28d9c5c8c /gcc/tree-ssa-phiopt.cc | |
| parent | 277456180ea4d002675a9498a7b1ec9d483ded73 (diff) | |
| download | gcc-68fa82e2d8f868a233103102dff2449a416bc566.zip gcc-68fa82e2d8f868a233103102dff2449a416bc566.tar.gz gcc-68fa82e2d8f868a233103102dff2449a416bc566.tar.bz2 | |
PHIOPT: Fix minmax_replacement for three way
So when diamond bb support was added to minmax_replacement in r13-1950-g9bb19e143cfe,
the code was not expecting the alt_middle_bb not to exist if it was empty (for threeway_p).
So when factor_out_conditional_conversion was used to factor out conversions, it turns out
the assumption for alt_middle_bb to be wrong and we ended up with threeway_p being true but
having middle_bb being empty but alt_middle_bb not being empty which causes wrong code in
many cases.
This patch fixes the issue by adding a test for the 2 cases where the assumption on
threeway_p case having the other bb being empty.
Changes made:
v2: Fix test for `(a <= u) b = MAX(a, d) else b = u`.
Note my plan for GCC 15 is remove minmax_replacement as match.pd will catch all cases
at that point.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/111469
gcc/ChangeLog:
* tree-ssa-phiopt.cc (minmax_replacement): Fix
the assumption for the `non-diamond` handling cases
of diamond code.
gcc/testsuite/ChangeLog:
* gcc.c-torture/execute/pr111469-1.c: New test.
Diffstat (limited to 'gcc/tree-ssa-phiopt.cc')
| -rw-r--r-- | gcc/tree-ssa-phiopt.cc | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc index 3835d25..312a6f9 100644 --- a/gcc/tree-ssa-phiopt.cc +++ b/gcc/tree-ssa-phiopt.cc @@ -1823,7 +1823,9 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, basic_block alt_ arg_false = arg0; } - if (empty_block_p (middle_bb)) + if (empty_block_p (middle_bb) + && (!threeway_p + || empty_block_p (alt_middle_bb))) { if ((operand_equal_for_phi_arg_p (arg_true, smaller) || (alt_smaller @@ -2006,7 +2008,8 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, basic_block alt_ return true; } - else + else if (!threeway_p + || empty_block_p (alt_middle_bb)) { /* Recognize the following case, assuming d <= u: @@ -2182,6 +2185,8 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb, basic_block alt_ SSA_OP_DEF)); gsi_move_before (&gsi_from, &gsi); } + else + return false; /* Emit the statement to compute min/max. */ gimple_seq stmts = NULL; |