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| author | Richard Biener <rguenther@suse.de> | 2020-11-09 15:19:56 +0100 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2020-11-10 09:31:46 +0100 |
| commit | 2686de5617bfb572343933be2883e8274c9735b5 (patch) | |
| tree | 68d5ec7cb26efbdcfa29457e2d1185de0878c177 /gcc | |
| parent | 3d3470e239e8040f642a8852721b4962b4ed36f2 (diff) | |
| download | gcc-2686de5617bfb572343933be2883e8274c9735b5.zip gcc-2686de5617bfb572343933be2883e8274c9735b5.tar.gz gcc-2686de5617bfb572343933be2883e8274c9735b5.tar.bz2 | |
tree-optimization/97760 - reduction paths with unhandled live stmt
This makes sure we reject reduction paths with a live stmt that
is not the last one altering the value. This is because we do not
handle this in the epilogue unless there's a scalar epilogue loop.
2020-11-09 Richard Biener <rguenther@suse.de>
PR tree-optimization/97760
* tree-vect-loop.c (check_reduction_path): Reject
reduction paths we do not handle in epilogue generation.
* gcc.dg/vect/pr97760.c: New testcase.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/testsuite/gcc.dg/vect/pr97760.c | 26 | ||||
| -rw-r--r-- | gcc/tree-vect-loop.c | 9 |
2 files changed, 32 insertions, 3 deletions
diff --git a/gcc/testsuite/gcc.dg/vect/pr97760.c b/gcc/testsuite/gcc.dg/vect/pr97760.c new file mode 100644 index 0000000..da5ac93 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/pr97760.c @@ -0,0 +1,26 @@ +#include "tree-vect.h" + +int b=1; +static int *g = &b; + +void __attribute__((noipa)) +h (unsigned int n) +{ + int i = 3; + int f = 3; + for (; f <= 50; f += 4) { + i += 4; + *g = i; + i += n; + } +} + +int main () +{ + check_vect (); + + h (9); + if (*g != 150 || b != 150) + __builtin_abort (); + return 0; +} diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c index 977633a..39b7319 100644 --- a/gcc/tree-vect-loop.c +++ b/gcc/tree-vect-loop.c @@ -3326,14 +3326,17 @@ pop: fail = true; break; } - /* Check there's only a single stmt the op is used on inside - of the loop. */ + /* Check there's only a single stmt the op is used on. For the + not value-changing tail and the last stmt allow out-of-loop uses. + ??? We could relax this and handle arbitrary live stmts by + forcing a scalar epilogue for example. */ imm_use_iterator imm_iter; gimple *op_use_stmt; unsigned cnt = 0; FOR_EACH_IMM_USE_STMT (op_use_stmt, imm_iter, op) if (!is_gimple_debug (op_use_stmt) - && flow_bb_inside_loop_p (loop, gimple_bb (op_use_stmt))) + && (*code != ERROR_MARK + || flow_bb_inside_loop_p (loop, gimple_bb (op_use_stmt)))) { /* We want to allow x + x but not x < 1 ? x : 2. */ if (is_gimple_assign (op_use_stmt) |