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| author | Yufeng Zhang <yufeng.zhang@arm.com> | 2013-10-25 17:25:08 +0000 |
|---|---|---|
| committer | Yufeng Zhang <yufeng@gcc.gnu.org> | 2013-10-25 17:25:08 +0000 |
| commit | 42917d01c097938d626e4c9728455c7f5d822280 (patch) | |
| tree | accdc86c368a7cdb19555cc714cf66b2b7c88f27 /gcc | |
| parent | b02ef56d8d792059f39bef1d9b853d9a2af0aa3b (diff) | |
| download | gcc-42917d01c097938d626e4c9728455c7f5d822280.zip gcc-42917d01c097938d626e4c9728455c7f5d822280.tar.gz gcc-42917d01c097938d626e4c9728455c7f5d822280.tar.bz2 | |
tree-ssa-math-opts.c (convert_plusminus_to_widen): Call has_single_use () and not do the conversion if...
gcc/
* tree-ssa-math-opts.c (convert_plusminus_to_widen): Call
has_single_use () and not do the conversion if has_single_use ()
returns false for the multiplication result.
gcc/testsuite/
* gcc.dg/wmul-1.c: New test.
From-SVN: r204072
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/wmul-1.c | 19 | ||||
| -rw-r--r-- | gcc/tree-ssa-math-opts.c | 15 |
4 files changed, 39 insertions, 5 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index dccf076..8b5eec8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2013-10-25 Yufeng Zhang <yufeng.zhang@arm.com> + + * tree-ssa-math-opts.c (convert_plusminus_to_widen): Call + has_single_use () and not do the conversion if has_single_use () + returns false for the multiplication result. + 2013-10-25 David Malcolm <dmalcolm@redhat.com> * tree.h (EXCEPTIONAL_CLASS_P): Rename parameter from "CODE" diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index ac5ab6d..3c27fcc 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2013-10-25 Yufeng Zhang <yufeng.zhang@arm.com> + + * gcc.dg/wmul-1.c: New test. + 2013-10-25 Paolo Carlini <paolo.carlini@oracle.com> PR c++/58878 diff --git a/gcc/testsuite/gcc.dg/wmul-1.c b/gcc/testsuite/gcc.dg/wmul-1.c new file mode 100644 index 0000000..3e762f4 --- /dev/null +++ b/gcc/testsuite/gcc.dg/wmul-1.c @@ -0,0 +1,19 @@ +/* Not to fuse widening multiply with accumulate if the multiply has more than + one uses. + Note that for targets where pointer and int are of the same size or + widening multiply-and-accumulate is not available, this test just passes. */ + +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-widening_mul" } */ + +typedef int ArrT [10][10]; + +void +foo (ArrT Arr, int Idx) +{ + Arr[Idx][Idx] = 1; + Arr[Idx + 10][Idx] = 2; +} + +/* { dg-final { scan-tree-dump-not "WIDEN_MULT_PLUS_EXPR" "widening_mul" } } */ +/* { dg-final { cleanup-tree-dump "widening_mul" } } */ diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c index 1817c20..9a29411 100644 --- a/gcc/tree-ssa-math-opts.c +++ b/gcc/tree-ssa-math-opts.c @@ -2432,20 +2432,25 @@ convert_plusminus_to_widen (gimple_stmt_iterator *gsi, gimple stmt, It might also appear that it would be sufficient to use the existing operands of the widening multiply, but that would limit the choice of - multiply-and-accumulate instructions. */ + multiply-and-accumulate instructions. + + If the widened-multiplication result has more than one uses, it is + probably wiser not to do the conversion. */ if (code == PLUS_EXPR && (rhs1_code == MULT_EXPR || rhs1_code == WIDEN_MULT_EXPR)) { - if (!is_widening_mult_p (rhs1_stmt, &type1, &mult_rhs1, - &type2, &mult_rhs2)) + if (!has_single_use (rhs1) + || !is_widening_mult_p (rhs1_stmt, &type1, &mult_rhs1, + &type2, &mult_rhs2)) return false; add_rhs = rhs2; conv_stmt = conv1_stmt; } else if (rhs2_code == MULT_EXPR || rhs2_code == WIDEN_MULT_EXPR) { - if (!is_widening_mult_p (rhs2_stmt, &type1, &mult_rhs1, - &type2, &mult_rhs2)) + if (!has_single_use (rhs2) + || !is_widening_mult_p (rhs2_stmt, &type1, &mult_rhs1, + &type2, &mult_rhs2)) return false; add_rhs = rhs1; conv_stmt = conv2_stmt; |