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| author | Pat Haugen <pthaugen@us.ibm.com> | 2016-11-10 18:55:57 +0000 |
|---|---|---|
| committer | Pat Haugen <pthaugen@gcc.gnu.org> | 2016-11-10 18:55:57 +0000 |
| commit | 8d34bfa865fb527b6a3569528656e2dc8af592e0 (patch) | |
| tree | 223b62a9c66bd4b015116cdb4548e792f4fe43a6 /gcc | |
| parent | a1566696653132892d629525644c2c63da8dab87 (diff) | |
| download | gcc-8d34bfa865fb527b6a3569528656e2dc8af592e0.zip gcc-8d34bfa865fb527b6a3569528656e2dc8af592e0.tar.gz gcc-8d34bfa865fb527b6a3569528656e2dc8af592e0.tar.bz2 | |
re PR rtl-optimization/78241 (wrong code with -funroll-loops)
PR rtl-optimization/78241
* loop-unroll.c (unroll_loop_runtime_iterations): Don't adjust 'niter', but
emit initial peel copy if niter expr is not reliable.
* gcc.dg/pr78241.c: New test.
From-SVN: r242047
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/loop-unroll.c | 9 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr78241.c | 20 |
4 files changed, 36 insertions, 4 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 66586e4..66ff361 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2016-11-10 Pat Haugen <pthaugen@us.ibm.com> + + PR rtl-optimization/78241 + * loop-unroll.c (unroll_loop_runtime_iterations): Don't adjust 'niter', but + emit initial peel copy if niter expr is not reliable. + 2016-11-10 Segher Boessenkool <segher@kernel.crashing.org> * dwarf2cfi.c (dump_cfi_row): Add forward declaration. diff --git a/gcc/loop-unroll.c b/gcc/loop-unroll.c index 91118a3..760445e 100644 --- a/gcc/loop-unroll.c +++ b/gcc/loop-unroll.c @@ -918,9 +918,10 @@ unroll_loop_runtime_iterations (struct loop *loop) if (tmp != niter) emit_move_insn (niter, tmp); - /* For loops that exit at end, add one to niter to account for first pass - through loop body before reaching exit test. */ - if (exit_at_end) + /* For loops that exit at end and whose number of iterations is reliable, + add one to niter to account for first pass through loop body before + reaching exit test. */ + if (exit_at_end && !desc->noloop_assumptions) { niter = expand_simple_binop (desc->mode, PLUS, niter, const1_rtx, @@ -946,7 +947,7 @@ unroll_loop_runtime_iterations (struct loop *loop) auto_sbitmap wont_exit (max_unroll + 2); - if (extra_zero_check) + if (extra_zero_check || desc->noloop_assumptions) { /* Peel the first copy of loop body. Leave the exit test if the number of iterations is not reliable. Also record the place of the extra zero diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index d522e24..b3f9442 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-11-10 Pat Haugen <pthaugen@us.ibm.com> + + PR rtl-optimization/78241 + * gcc.dg/pr78241.c: New test. + 2016-11-10 Jakub Jelinek <jakub@redhat.com> * gfortran.dg/openmp-define-3.f90: Expect 201511 instead of diff --git a/gcc/testsuite/gcc.dg/pr78241.c b/gcc/testsuite/gcc.dg/pr78241.c new file mode 100644 index 0000000..b99dfca --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr78241.c @@ -0,0 +1,20 @@ +/* { dg-do run } */ +/* { dg-options "-Og -funroll-loops" } */ + +static __attribute__((noinline, noclone)) unsigned +foo (unsigned x) +{ + do + x++; + while (x <= 15); + return x; +} + +int main () +{ + unsigned x = foo (-2); + if (x != (unsigned)-1) + __builtin_abort(); + return 0; +} + |