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| author | Sanjay Patel <spatel@rotateright.com> | 2017-05-24 14:56:51 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2017-05-24 14:56:51 +0000 |
| commit | 6232406b34335a613011fcd828b67d2e9ac4b0a2 (patch) | |
| tree | b33b61a88c0323bb1292b04b47ed1ff09c5fbe89 /llvm/test/Transforms | |
| parent | 8973a0a22ca6e1764bf7f0d87460420cbcc80c9e (diff) | |
| download | bcm5719-llvm-6232406b34335a613011fcd828b67d2e9ac4b0a2.tar.gz bcm5719-llvm-6232406b34335a613011fcd828b67d2e9ac4b0a2.zip | |
[InstCombine] add tests to show potential missing folds; NFC
As noted in https://bugs.llvm.org/show_bug.cgi?id=33138 and
the comments, there are multiple ways to view this. If we
choose not to solve this in InstCombine, these tests will
serve as documentation of that choice.
llvm-svn: 303755
Diffstat (limited to 'llvm/test/Transforms')
| -rw-r--r-- | llvm/test/Transforms/InstCombine/icmp-xor-signbit.ll | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/llvm/test/Transforms/InstCombine/icmp-xor-signbit.ll b/llvm/test/Transforms/InstCombine/icmp-xor-signbit.ll index 548d1232bb8..30a9668f37d 100644 --- a/llvm/test/Transforms/InstCombine/icmp-xor-signbit.ll +++ b/llvm/test/Transforms/InstCombine/icmp-xor-signbit.ll @@ -187,3 +187,42 @@ define <2 x i1> @uge_to_slt_splat(<2 x i8> %x) { ret <2 x i1> %cmp } +; PR33138, part 2: https://bugs.llvm.org/show_bug.cgi?id=33138 +; TODO: We could look through vector bitcasts for icmp folds, +; or we could canonicalize bitcast ahead of logic ops with constants. + +define <8 x i1> @sgt_to_ugt_bitcasted_splat(<2 x i32> %x, <2 x i32> %y) { +; CHECK-LABEL: @sgt_to_ugt_bitcasted_splat( +; CHECK-NEXT: [[A:%.*]] = xor <2 x i32> %x, <i32 -2139062144, i32 -2139062144> +; CHECK-NEXT: [[B:%.*]] = xor <2 x i32> %y, <i32 -2139062144, i32 -2139062144> +; CHECK-NEXT: [[C:%.*]] = bitcast <2 x i32> [[A]] to <8 x i8> +; CHECK-NEXT: [[D:%.*]] = bitcast <2 x i32> [[B]] to <8 x i8> +; CHECK-NEXT: [[E:%.*]] = icmp sgt <8 x i8> [[C]], [[D]] +; CHECK-NEXT: ret <8 x i1> [[E]] +; + %a = xor <2 x i32> %x, <i32 2155905152, i32 2155905152> ; 0x80808080 + %b = xor <2 x i32> %y, <i32 2155905152, i32 2155905152> + %c = bitcast <2 x i32> %a to <8 x i8> + %d = bitcast <2 x i32> %b to <8 x i8> + %e = icmp sgt <8 x i8> %c, %d + ret <8 x i1> %e +} + +; TODO: This is false (little-endian). How should that be recognized? +; Ie, should InstSimplify know this directly, should InstCombine canonicalize +; this so InstSimplify can know this, or is that not something that we want +; either pass to recognize? + +define <2 x i1> @negative_simplify_splat(<4 x i8> %x) { +; CHECK-LABEL: @negative_simplify_splat( +; CHECK-NEXT: [[A:%.*]] = or <4 x i8> %x, <i8 0, i8 -128, i8 0, i8 -128> +; CHECK-NEXT: [[B:%.*]] = bitcast <4 x i8> [[A]] to <2 x i16> +; CHECK-NEXT: [[C:%.*]] = icmp sgt <2 x i16> [[B]], zeroinitializer +; CHECK-NEXT: ret <2 x i1> [[C]] +; + %a = or <4 x i8> %x, <i8 0, i8 128, i8 0, i8 128> + %b = bitcast <4 x i8> %a to <2 x i16> + %c = icmp sgt <2 x i16> %b, zeroinitializer + ret <2 x i1> %c +} + |
