diff options
| author | Sanjoy Das <sanjoy@playingwithpointers.com> | 2015-01-06 19:02:56 +0000 |
|---|---|---|
| committer | Sanjoy Das <sanjoy@playingwithpointers.com> | 2015-01-06 19:02:56 +0000 |
| commit | 7c0ce26614af63cf450fecf44c7ed088d7fb3b06 (patch) | |
| tree | 7a882cbd0ad8f96c1e3199953368e6cd6d49290c /llvm/test/Transforms/BBVectorize | |
| parent | 4e781371d11a1b773ac8e90706129daf9f1f0621 (diff) | |
| download | bcm5719-llvm-7c0ce26614af63cf450fecf44c7ed088d7fb3b06.tar.gz bcm5719-llvm-7c0ce26614af63cf450fecf44c7ed088d7fb3b06.zip | |
This patch teaches IndVarSimplify to add nuw and nsw to certain kinds
of operations that provably don't overflow. For example, we can prove
%civ.inc below does not sign-overflow. With this change,
IndVarSimplify changes %civ.inc to an add nsw.
define i32 @foo(i32* %array, i32* %length_ptr, i32 %init) {
entry:
%length = load i32* %length_ptr, !range !0
%len.sub.1 = sub i32 %length, 1
%upper = icmp slt i32 %init, %len.sub.1
br i1 %upper, label %loop, label %exit
loop:
%civ = phi i32 [ %init, %entry ], [ %civ.inc, %latch ]
%civ.inc = add i32 %civ, 1
%cmp = icmp slt i32 %civ.inc, %length
br i1 %cmp, label %latch, label %break
latch:
store i32 0, i32* %array
%check = icmp slt i32 %civ.inc, %len.sub.1
br i1 %check, label %loop, label %break
break:
ret i32 %civ.inc
exit:
ret i32 42
}
Differential Revision: http://reviews.llvm.org/D6748
llvm-svn: 225282
Diffstat (limited to 'llvm/test/Transforms/BBVectorize')
| -rw-r--r-- | llvm/test/Transforms/BBVectorize/loop1.ll | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/llvm/test/Transforms/BBVectorize/loop1.ll b/llvm/test/Transforms/BBVectorize/loop1.ll index ed7be15f7ad..ca361703adc 100644 --- a/llvm/test/Transforms/BBVectorize/loop1.ll +++ b/llvm/test/Transforms/BBVectorize/loop1.ll @@ -83,7 +83,7 @@ for.body: ; preds = %for.body, %entry ; CHECK-UNRL: %add12 = fadd <2 x double> %add7, %mul11 ; CHECK-UNRL: %4 = bitcast double* %arrayidx14 to <2 x double>* ; CHECK-UNRL: store <2 x double> %add12, <2 x double>* %4, align 8 -; CHECK-UNRL: %indvars.iv.next.1 = add i64 %indvars.iv, 2 +; CHECK-UNRL: %indvars.iv.next.1 = add nsw i64 %indvars.iv, 2 ; CHECK-UNRL: %lftr.wideiv.1 = trunc i64 %indvars.iv.next.1 to i32 ; CHECK-UNRL: %exitcond.1 = icmp eq i32 %lftr.wideiv.1, 10 ; CHECK-UNRL: br i1 %exitcond.1, label %for.end, label %for.body |
