| Message ID | 9f3e00ae-a0c7-0047-c2e7-6578d9300171@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Mon, Aug 8, 2016 at 3:41 AM, kugan <kugan.vivekanandarajah@linaro.org> wrote: > Hi All, > > I was experimenting with using ccp mask and value to refine value_ranges for > SSA_NAME. Attached patch does this. This might be particularly useful for > early_vrp. Bootstrap on x86_64-linux-gnu is OK. However, there are some > test-cases (as shown below) are failing. > > > Is this worth investigating? Any thoughts? > > # Comparing directories > ## Dir1=build-base/: 11 sum files > ## Dir2=build: 11 sum files > > # Comparing 11 common sum files > ## /bin/sh ./gcc/contrib/compare_tests /tmp/gxx-sum1.26167 > /tmp/gxx-sum2.26167 > Tests that now fail, but worked before: > > gcc.c-torture/execute/pr57124.c -O2 execution test > gcc.c-torture/execute/pr57124.c -O2 -flto -fno-use-linker-plugin > -flto-partition=none execution test > gcc.c-torture/execute/pr57124.c -O3 -g execution test > gcc.c-torture/execute/pr57124.c -Os execution test > gcc.dg/Wstrict-overflow-12.c correct warning (test for warnings, line 13) > gcc.dg/Wstrict-overflow-13.c correct warning (test for warnings, line 14) > gcc.dg/Wstrict-overflow-21.c correct warning (test for warnings, line 8) > gcc.dg/no-strict-overflow-6.c scan-tree-dump optimized "return 0" > gcc.dg/tree-ssa/pr61743-1.c scan-tree-dump-times cunroll "loop with 4 > iterations completely unrolled" 2 > gcc.dg/tree-ssa/pr61743-1.c scan-tree-dump-times cunroll "loop with 8 > iterations completely unrolled" 2 > gcc.dg/tree-ssa/ssa-dom-thread-7.c scan-tree-dump thread3 "Jumps threaded: > 3" Esp. the execute fail need to be investigated of course. I'd have done it similar to set_range_info improving nonzero_bits, thus, have set_nonzero_bits improve range_info rather than introducing a new refine_range_info or if that doesn't do anything useful without also knowing the known-ones then inline this all into the single caller in CCP or provide an optional arg to set_nonzero_bits with the missing information. Richard. > ## Differences found: > # 1 differences in 11 common sum files found > > > Thanks, > Kugan > > > gcc/ChangeLog: > > 2016-08-08 Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org> > > * tree-ssanames.c (refine_range_info): New. > * tree-ssa-ccp.c (ccp_finalize): Call refine_range_info. > * tree-ssanames.c (refine_range_info): Declare. >
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c index ae120a8..e7326c7 100644 --- a/gcc/tree-ssa-ccp.c +++ b/gcc/tree-ssa-ccp.c @@ -940,8 +940,14 @@ ccp_finalize (bool nonzero_p) unsigned int precision = TYPE_PRECISION (TREE_TYPE (val->value)); wide_int nonzero_bits = wide_int::from (val->mask, precision, UNSIGNED) | val->value; + wide_int mask = wide_int::from (val->mask, TYPE_PRECISION (TREE_TYPE (name)), + TYPE_SIGN (TREE_TYPE (name))); + wide_int ones = wi::bit_and (val->value, wi::bit_not (mask)); + wide_int zeros = wi::bit_not (wi::bit_and (wi::bit_not (val->value), + wi::bit_not (mask))); nonzero_bits &= get_nonzero_bits (name); set_nonzero_bits (name, nonzero_bits); + refine_range_info (name, zeros, ones); } } diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c index 91a8f97..a69d8e9 100644 --- a/gcc/tree-ssanames.c +++ b/gcc/tree-ssanames.c @@ -388,6 +388,36 @@ set_nonzero_bits (tree name, const wide_int_ref &mask) ri->set_nonzero_bits (mask); } +/* Refine value range of NAME based on allways ZEROS and always ONES bits. */ +void +refine_range_info (tree name, const wide_int_ref &zeros, + const wide_int_ref &ones) +{ + tree type = TREE_TYPE (name); + gcc_assert (!POINTER_TYPE_P (TREE_TYPE (name))); + if (SSA_NAME_RANGE_INFO (name) == NULL) + set_range_info (name, VR_RANGE, + TYPE_MIN_VALUE (type), + TYPE_MAX_VALUE (type)); + + if (SSA_NAME_RANGE_TYPE (name) != VR_RANGE) + return; + + wide_int min = wi::min_value (type); + wide_int max = wi::max_value (type); + + max &= zeros; + max |= ones; + min &= zeros; + min |= ones; + + range_info_def *ri = SSA_NAME_RANGE_INFO (name); + if (wi::cmp (ri->get_min(), min, TYPE_SIGN (TREE_TYPE (name))) == -1) + ri->set_min (min); + if (wi::cmp (max, ri->get_max(), TYPE_SIGN (TREE_TYPE (name))) == -1) + ri->set_max (max); +} + /* Return a widest_int with potentially non-zero bits in SSA_NAME NAME, or -1 if unknown. */ diff --git a/gcc/tree-ssanames.h b/gcc/tree-ssanames.h index c81b1a1..c18047a 100644 --- a/gcc/tree-ssanames.h +++ b/gcc/tree-ssanames.h @@ -74,6 +74,8 @@ extern void set_range_info (tree, enum value_range_type, const wide_int_ref &, extern enum value_range_type get_range_info (const_tree, wide_int *, wide_int *); extern void set_nonzero_bits (tree, const wide_int_ref &); +extern void refine_range_info (tree name, const wide_int_ref &zeros, + const wide_int_ref &ones); extern wide_int get_nonzero_bits (const_tree); extern bool ssa_name_has_boolean_range (tree); extern void init_ssanames (struct function *, int);