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| author | Richard Biener <rguenther@suse.de> | 2019-08-20 12:02:56 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2019-08-20 12:02:56 +0000 |
| commit | 3ed01d5408045d80a1efc42fadacfcfb98f14997 (patch) | |
| tree | 5a8134073d50509866bc11b02a3f768d98a2a994 /gcc | |
| parent | a53aa4da8add4e3adc6c38f70eb172d570865831 (diff) | |
| download | gcc-3ed01d5408045d80a1efc42fadacfcfb98f14997.zip gcc-3ed01d5408045d80a1efc42fadacfcfb98f14997.tar.gz gcc-3ed01d5408045d80a1efc42fadacfcfb98f14997.tar.bz2 | |
re PR tree-optimization/37242 (missed FRE opportunity because of signedness of addition)
2019-08-20 Richard Biener <rguenther@suse.de>
PR tree-optimization/37242
* tree-ssa-sccvn.c (visit_nary_op): Also CSE (T)(a + b)
to (T)a + (T)b if we know that a + b does not overflow.
* gcc.dg/tree-ssa/ssa-fre-80.c: New testcase.
From-SVN: r274746
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-80.c | 16 | ||||
| -rw-r--r-- | gcc/tree-ssa-sccvn.c | 12 |
4 files changed, 36 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7130cda..b750de4 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2019-08-20 Richard Biener <rguenther@suse.de> + + PR tree-optimization/37242 + * tree-ssa-sccvn.c (visit_nary_op): Also CSE (T)(a + b) + to (T)a + (T)b if we know that a + b does not overflow. + 2019-08-20 Eric Botcazou <ebotcazou@adacore.com> PR rtl-optimization/91347 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index f18ea5f..5316e07 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2019-08-20 Richard Biener <rguenther@suse.de> + + PR tree-optimization/37242 + * gcc.dg/tree-ssa/ssa-fre-80.c: New testcase. + 2019-08-20 Ed Schonberg <schonberg@adacore.com> * gnat.dg/storage_size1.adb: New testcase. diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-80.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-80.c new file mode 100644 index 0000000..0176508 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-80.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-fre1" } */ + +unsigned long a, b; +void foo (int m, int f) +{ + unsigned long tem = (unsigned long)m; + a = tem + 1; + if (f) + { + int tem2 = m + 1; + b = (unsigned long)tem2; /* Eliminated to a. */ + } +} + +/* { dg-final { scan-tree-dump-times "\\(long unsigned int\\)" 1 "fre1" } } */ diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index eb7e4be..76cad43 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -4312,8 +4312,12 @@ visit_nary_op (tree lhs, gassign *stmt) operation. */ if (INTEGRAL_TYPE_P (type) && TREE_CODE (rhs1) == SSA_NAME - /* We only handle sign-changes or zero-extension -> & mask. */ - && ((TYPE_UNSIGNED (TREE_TYPE (rhs1)) + /* We only handle sign-changes, zero-extension -> & mask or + sign-extension if we know the inner operation doesn't + overflow. */ + && (((TYPE_UNSIGNED (TREE_TYPE (rhs1)) + || (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) + && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (rhs1)))) && TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (rhs1))) || TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (rhs1)))) { @@ -4347,7 +4351,9 @@ visit_nary_op (tree lhs, gassign *stmt) { unsigned lhs_prec = TYPE_PRECISION (type); unsigned rhs_prec = TYPE_PRECISION (TREE_TYPE (rhs1)); - if (lhs_prec == rhs_prec) + if (lhs_prec == rhs_prec + || (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) + && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (rhs1)))) { gimple_match_op match_op (gimple_match_cond::UNCOND, NOP_EXPR, type, ops[0]); |