diff options
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr102087.c | 35 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop-niter.c | 16 |
2 files changed, 50 insertions, 1 deletions
diff --git a/gcc/testsuite/gcc.dg/pr102087.c b/gcc/testsuite/gcc.dg/pr102087.c new file mode 100644 index 0000000..5cd094f --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr102087.c @@ -0,0 +1,35 @@ +/* { dg-do compile } */ +/* { dg-options "-O3" } */ + +unsigned __attribute__ ((noinline)) +foo (int *__restrict__ a, int *__restrict__ b, unsigned l, unsigned n) +{ + while (n < ++l) + *a++ = *b++ + 1; + return l; +} + +volatile int a[1]; +unsigned b; +int c; + +int +check () +{ + int d; + for (; b > 1; b++) + for (c = 0; c < 2; c++) + for (d = 0; d < 2; d++) + a[0]; + return 0; +} + +char **clip_image_gfi_0; +int clip_image_y, clip_image_shift; +void +clip_image () +{ + for (; clip_image_y >= clip_image_shift; clip_image_y++) + clip_image_gfi_0[clip_image_shift] + = clip_image_gfi_0[clip_image_y]; +} diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c index 7af92d1..7510940 100644 --- a/gcc/tree-ssa-loop-niter.c +++ b/gcc/tree-ssa-loop-niter.c @@ -1482,7 +1482,7 @@ number_of_iterations_until_wrap (class loop *, tree type, affine_iv *iv0, affine_iv *iv1, class tree_niter_desc *niter) { tree niter_type = unsigned_type_for (type); - tree step, num, assumptions, may_be_zero; + tree step, num, assumptions, may_be_zero, span; wide_int high, low, max, min; may_be_zero = fold_build2 (LE_EXPR, boolean_type_node, iv1->base, iv0->base); @@ -1557,6 +1557,20 @@ number_of_iterations_until_wrap (class loop *, tree type, affine_iv *iv0, niter->control.no_overflow = false; + /* Update bound and exit condition as: + bound = niter * STEP + (IVbase - STEP). + { IVbase - STEP, +, STEP } != bound + Here, biasing IVbase by 1 step makes 'bound' be the value before wrap. + */ + niter->control.base = fold_build2 (MINUS_EXPR, niter_type, + niter->control.base, niter->control.step); + span = fold_build2 (MULT_EXPR, niter_type, niter->niter, + fold_convert (niter_type, niter->control.step)); + niter->bound = fold_build2 (PLUS_EXPR, niter_type, span, + fold_convert (niter_type, niter->control.base)); + niter->bound = fold_convert (type, niter->bound); + niter->cmp = NE_EXPR; + return true; } |