Message ID | 20150127104729.GC47190@msticlxl57.ims.intel.com |
---|---|
State | New |
Headers | show |
On Tue, Jan 27, 2015 at 11:47 AM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote: > On 27 Jan 12:40, Ilya Enkovich wrote: >> Hi, >> >> This patch was supposed to fix PR tree-optimization/64277. Tracker is now fixed by warnings disabling but I think patch is still useful to avoid dead code generated by complete unroll. >> >> Bootstrapped and tested on x86_64-unknown-linux-gnu. >> >> Thanks, >> Ilya >> -- >> gcc/ >> >> 2015-01-27 Ilya Enkovich <ilya.enkovich@intel.com> >> >> * tree-ssa-loop-niter.c (record_nonwrapping_iv): Use base >> range info when possible to refine estimation. >> >> gcc/testsuite/ >> >> 2015-01-27 Ilya Enkovich <ilya.enkovich@intel.com> >> >> * gcc.dg/pr64277.c: New. >> >> > > Here is a new version fixed according to comments in the tracker. I also fixed a test to scan cunroll dumps. Does it look OK? Minor comments below. > What are possible branches for this patch? You can probably create a testcase that shows code-size regressions against a version that didn't peel completely (GCC 4.7). Thus I'd say it would apply to 4.9 as well (4.8 doesn't have range information). > Thanks, > Ilya > -- > diff --git a/gcc/testsuite/gcc.dg/pr64277.c b/gcc/testsuite/gcc.dg/pr64277.c > new file mode 100644 > index 0000000..c6ef331 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/pr64277.c > @@ -0,0 +1,23 @@ > +/* PR tree-optimization/64277 */ > +/* { dg-do compile } */ > +/* { dg-options "-O3 -Wall -Werror -fdump-tree-cunroll-details" } */ > +/* { dg-final { scan-tree-dump "loop with 5 iterations completely unrolled" "cunroll" } } */ > +/* { dg-final { scan-tree-dump "loop with 6 iterations completely unrolled" "cunroll" } } */ > +/* { dg-final { cleanup-tree-dump "cunroll" } } */ > + > +int f1[10]; > +void test1 (short a[], short m, unsigned short l) > +{ > + int i = l; > + for (i = i + 5; i < m; i++) > + f1[i] = a[i]++; > +} > + > +void test2 (short a[], short m, short l) > +{ > + int i; > + if (m > 5) > + m = 5; > + for (i = m; i > l; i--) > + f1[i] = a[i]++; > +} > diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c > index 919f5c0..1cd297d 100644 > --- a/gcc/tree-ssa-loop-niter.c > +++ b/gcc/tree-ssa-loop-niter.c > @@ -2754,6 +2754,7 @@ record_nonwrapping_iv (struct loop *loop, tree base, tree step, gimple stmt, > { > tree niter_bound, extreme, delta; > tree type = TREE_TYPE (base), unsigned_type; > + tree orig_base = base; > > if (TREE_CODE (step) != INTEGER_CST || integer_zerop (step)) > return; > @@ -2777,16 +2778,30 @@ record_nonwrapping_iv (struct loop *loop, tree base, tree step, gimple stmt, > > if (tree_int_cst_sign_bit (step)) > { > + wide_int min, max; > extreme = fold_convert (unsigned_type, low); > - if (TREE_CODE (base) != INTEGER_CST) > + if (TREE_CODE (orig_base) == SSA_NAME > + && TREE_CODE (high) == INTEGER_CST > + && INTEGRAL_TYPE_P (TREE_TYPE (orig_base)) > + && get_range_info (orig_base, &min, &max) == VR_RANGE > + && wi::gts_p (wide_int (high), max)) For me a simple wi::gts_p (high, max) worked fine. > + base = wide_int_to_tree (unsigned_type, max); > + else if (TREE_CODE (base) != INTEGER_CST) > base = fold_convert (unsigned_type, high); > delta = fold_build2 (MINUS_EXPR, unsigned_type, base, extreme); > step = fold_build1 (NEGATE_EXPR, unsigned_type, step); > } > else > { > + wide_int min, max; > extreme = fold_convert (unsigned_type, high); > - if (TREE_CODE (base) != INTEGER_CST) > + if (TREE_CODE (orig_base) == SSA_NAME > + && TREE_CODE (low) == INTEGER_CST > + && INTEGRAL_TYPE_P (TREE_TYPE (orig_base)) > + && get_range_info (orig_base, &min, &max) == VR_RANGE > + && wi::gts_p (min, wide_int (low))) Likewise. Ok for trunk with that changes. For the 4.9 branch you need to adjust the patch to not use wide-ints. I'd leave it on trunk for a while and eventually open a bugreport for the size regression to keep track of it. Thanks, Richard. > + base = wide_int_to_tree (unsigned_type, min); > + else if (TREE_CODE (base) != INTEGER_CST) > base = fold_convert (unsigned_type, low); > delta = fold_build2 (MINUS_EXPR, unsigned_type, extreme, base); > }
diff --git a/gcc/testsuite/gcc.dg/pr64277.c b/gcc/testsuite/gcc.dg/pr64277.c new file mode 100644 index 0000000..c6ef331 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr64277.c @@ -0,0 +1,23 @@ +/* PR tree-optimization/64277 */ +/* { dg-do compile } */ +/* { dg-options "-O3 -Wall -Werror -fdump-tree-cunroll-details" } */ +/* { dg-final { scan-tree-dump "loop with 5 iterations completely unrolled" "cunroll" } } */ +/* { dg-final { scan-tree-dump "loop with 6 iterations completely unrolled" "cunroll" } } */ +/* { dg-final { cleanup-tree-dump "cunroll" } } */ + +int f1[10]; +void test1 (short a[], short m, unsigned short l) +{ + int i = l; + for (i = i + 5; i < m; i++) + f1[i] = a[i]++; +} + +void test2 (short a[], short m, short l) +{ + int i; + if (m > 5) + m = 5; + for (i = m; i > l; i--) + f1[i] = a[i]++; +} diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c index 919f5c0..1cd297d 100644 --- a/gcc/tree-ssa-loop-niter.c +++ b/gcc/tree-ssa-loop-niter.c @@ -2754,6 +2754,7 @@ record_nonwrapping_iv (struct loop *loop, tree base, tree step, gimple stmt, { tree niter_bound, extreme, delta; tree type = TREE_TYPE (base), unsigned_type; + tree orig_base = base; if (TREE_CODE (step) != INTEGER_CST || integer_zerop (step)) return; @@ -2777,16 +2778,30 @@ record_nonwrapping_iv (struct loop *loop, tree base, tree step, gimple stmt, if (tree_int_cst_sign_bit (step)) { + wide_int min, max; extreme = fold_convert (unsigned_type, low); - if (TREE_CODE (base) != INTEGER_CST) + if (TREE_CODE (orig_base) == SSA_NAME + && TREE_CODE (high) == INTEGER_CST + && INTEGRAL_TYPE_P (TREE_TYPE (orig_base)) + && get_range_info (orig_base, &min, &max) == VR_RANGE + && wi::gts_p (wide_int (high), max)) + base = wide_int_to_tree (unsigned_type, max); + else if (TREE_CODE (base) != INTEGER_CST) base = fold_convert (unsigned_type, high); delta = fold_build2 (MINUS_EXPR, unsigned_type, base, extreme); step = fold_build1 (NEGATE_EXPR, unsigned_type, step); } else { + wide_int min, max; extreme = fold_convert (unsigned_type, high); - if (TREE_CODE (base) != INTEGER_CST) + if (TREE_CODE (orig_base) == SSA_NAME + && TREE_CODE (low) == INTEGER_CST + && INTEGRAL_TYPE_P (TREE_TYPE (orig_base)) + && get_range_info (orig_base, &min, &max) == VR_RANGE + && wi::gts_p (min, wide_int (low))) + base = wide_int_to_tree (unsigned_type, min); + else if (TREE_CODE (base) != INTEGER_CST) base = fold_convert (unsigned_type, low); delta = fold_build2 (MINUS_EXPR, unsigned_type, extreme, base); }