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| author | David Majnemer <david.majnemer@gmail.com> | 2015-04-22 22:42:05 +0000 |
|---|---|---|
| committer | David Majnemer <david.majnemer@gmail.com> | 2015-04-22 22:42:05 +0000 |
| commit | 7d0e99c6019ca1c4c6708309ef5dade0db03b425 (patch) | |
| tree | ab617ef7dee6f4e251678779e1cbe578abb7d2c0 /llvm/test/Transforms/InstCombine | |
| parent | 64a2a6a473553f178b74c785722d4f8dfd6b9eb1 (diff) | |
| download | bcm5719-llvm-7d0e99c6019ca1c4c6708309ef5dade0db03b425.tar.gz bcm5719-llvm-7d0e99c6019ca1c4c6708309ef5dade0db03b425.zip | |
[InstCombine] Use a more targeted fix instead of r235544
Only clear out the NSW/NUW flags if we are optimizing 'add'/'sub' while
taking advantage that the sign bit is not set. We do this optimization
to further shrink the mask but shrinking the mask isn't NSW/NUW
preserving in this case.
llvm-svn: 235558
Diffstat (limited to 'llvm/test/Transforms/InstCombine')
| -rw-r--r-- | llvm/test/Transforms/InstCombine/cast.ll | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/cast.ll b/llvm/test/Transforms/InstCombine/cast.ll index 7bf4a6047f2..8a4a60e8753 100644 --- a/llvm/test/Transforms/InstCombine/cast.ll +++ b/llvm/test/Transforms/InstCombine/cast.ll @@ -1125,3 +1125,15 @@ define i1 @PR23309(i32 %A, i32 %B) { %trunc = trunc i32 %sub to i1 ret i1 %trunc } + +define i1 @PR23309v2(i32 %A, i32 %B) { +; CHECK-LABEL: @PR23309v2( +; CHECK-NEXT: %[[sub:.*]] = add i32 %A, %B +; CHECK-NEXT: %[[and:.*]] = and i32 %[[sub]], 1 +; CHECK-NEXT: %[[cmp:.*]] = icmp ne i32 %[[and]], 0 +; CHECK-NEXT: ret i1 %[[cmp]] + %add = add i32 %A, -4 + %sub = add nuw i32 %add, %B + %trunc = trunc i32 %sub to i1 + ret i1 %trunc +} |
