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| author | Richard Earnshaw <rearnsha@arm.com> | 2012-09-07 10:37:08 +0000 |
|---|---|---|
| committer | Richard Earnshaw <rearnsha@gcc.gnu.org> | 2012-09-07 10:37:08 +0000 |
| commit | e919e5bffbc8acd81d795e5c5a50d3d785bcdf0f (patch) | |
| tree | c6a5cc1bbe9e0d190e009cb18cb51b75417511aa /gcc/tree-ssa-math-opts.c | |
| parent | 81ab73121e775ca961650a7eb4656b5075a492c5 (diff) | |
| download | gcc-e919e5bffbc8acd81d795e5c5a50d3d785bcdf0f.zip gcc-e919e5bffbc8acd81d795e5c5a50d3d785bcdf0f.tar.gz gcc-e919e5bffbc8acd81d795e5c5a50d3d785bcdf0f.tar.bz2 | |
re PR tree-optimization/54295 (Widening multiply-accumulate operation uses wrong value extension)
PR tree-ssa/54295
* tree-ssa-math-opts.c (widening_mult_conversion_strippable_p):
Sign-extension of a zero-extended value can be simplified to
just zero-extension.
testsuite:
* gcc.target/arm/pr50318-1.c: Scan for smlal.
* gcc.target/arm/smlaltb-1.c: XFAIL test.
* gcc.target/arm/smlaltt-1.c: Likewise.
From-SVN: r191066
Diffstat (limited to 'gcc/tree-ssa-math-opts.c')
| -rw-r--r-- | gcc/tree-ssa-math-opts.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c index c3392fb..94d19af 100644 --- a/gcc/tree-ssa-math-opts.c +++ b/gcc/tree-ssa-math-opts.c @@ -1985,7 +1985,11 @@ widening_mult_conversion_strippable_p (tree result_type, gimple stmt) the operation and doesn't narrow the range. */ inner_op_type = TREE_TYPE (gimple_assign_rhs1 (stmt)); - if (TYPE_UNSIGNED (op_type) == TYPE_UNSIGNED (inner_op_type) + /* If the inner-most type is unsigned, then we can strip any + intermediate widening operation. If it's signed, then the + intermediate widening operation must also be signed. */ + if ((TYPE_UNSIGNED (inner_op_type) + || TYPE_UNSIGNED (op_type) == TYPE_UNSIGNED (inner_op_type)) && TYPE_PRECISION (op_type) > TYPE_PRECISION (inner_op_type)) return true; |