diff options
| author | Sanjay Patel <spatel@rotateright.com> | 2016-06-27 22:27:11 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2016-06-27 22:27:11 +0000 |
| commit | 59ed2ffca38f01b326459d366d1b131ec45eb483 (patch) | |
| tree | 480c5bebdf739530d2b2e42e14e0aa19592092b7 /llvm/test | |
| parent | a657f875a91b652adb3a373265db2745c1e7680d (diff) | |
| download | bcm5719-llvm-59ed2ffca38f01b326459d366d1b131ec45eb483.tar.gz bcm5719-llvm-59ed2ffca38f01b326459d366d1b131ec45eb483.zip | |
[InstCombine] shrink type of sdiv if dividend is sexted and constant divisor is small enough (PR28153)
This should fix PR28153:
https://llvm.org/bugs/show_bug.cgi?id=28153
Differential Revision: http://reviews.llvm.org/D21769
llvm-svn: 273951
Diffstat (limited to 'llvm/test')
| -rw-r--r-- | llvm/test/Transforms/InstCombine/div.ll | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/llvm/test/Transforms/InstCombine/div.ll b/llvm/test/Transforms/InstCombine/div.ll index 4ad7005da20..a19cdefa31f 100644 --- a/llvm/test/Transforms/InstCombine/div.ll +++ b/llvm/test/Transforms/InstCombine/div.ll @@ -409,13 +409,12 @@ lor.end: ; preds = %lor.rhs, %entry ret i32 %div } -; FIXME: ; We can perform the division in the smaller type. define i32 @shrink(i8 %x) { ; CHECK-LABEL: @shrink( -; CHECK-NEXT: [[CONV:%.*]] = sext i8 %x to i32 -; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 [[CONV]], 127 +; CHECK-NEXT: [[TMP1:%.*]] = sdiv i8 %x, 127 +; CHECK-NEXT: [[DIV:%.*]] = sext i8 [[TMP1]] to i32 ; CHECK-NEXT: ret i32 [[DIV]] ; %conv = sext i8 %x to i32 @@ -427,8 +426,8 @@ define i32 @shrink(i8 %x) { define i32 @zap(i8 %x) { ; CHECK-LABEL: @zap( -; CHECK-NEXT: [[CONV:%.*]] = sext i8 %x to i32 -; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 [[CONV]], -128 +; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i8 %x, -128 +; CHECK-NEXT: [[DIV:%.*]] = zext i1 [[TMP1]] to i32 ; CHECK-NEXT: ret i32 [[DIV]] ; %conv = sext i8 %x to i32 @@ -440,8 +439,8 @@ define i32 @zap(i8 %x) { define <3 x i32> @shrink_vec(<3 x i8> %x) { ; CHECK-LABEL: @shrink_vec( -; CHECK-NEXT: [[CONV:%.*]] = sext <3 x i8> %x to <3 x i32> -; CHECK-NEXT: [[DIV:%.*]] = sdiv <3 x i32> [[CONV]], <i32 127, i32 127, i32 127> +; CHECK-NEXT: [[TMP1:%.*]] = sdiv <3 x i8> %x, <i8 127, i8 127, i8 127> +; CHECK-NEXT: [[DIV:%.*]] = sext <3 x i8> [[TMP1]] to <3 x i32> ; CHECK-NEXT: ret <3 x i32> [[DIV]] ; %conv = sext <3 x i8> %x to <3 x i32> @@ -451,8 +450,8 @@ define <3 x i32> @shrink_vec(<3 x i8> %x) { define <2 x i32> @zap_vec(<2 x i8> %x) { ; CHECK-LABEL: @zap_vec( -; CHECK-NEXT: [[CONV:%.*]] = sext <2 x i8> %x to <2 x i32> -; CHECK-NEXT: [[DIV:%.*]] = sdiv <2 x i32> [[CONV]], <i32 -128, i32 -128> +; CHECK-NEXT: [[TMP1:%.*]] = icmp eq <2 x i8> %x, <i8 -128, i8 -128> +; CHECK-NEXT: [[DIV:%.*]] = zext <2 x i1> [[TMP1]] to <2 x i32> ; CHECK-NEXT: ret <2 x i32> [[DIV]] ; %conv = sext <2 x i8> %x to <2 x i32> @@ -484,3 +483,16 @@ define i32 @shrink_no2(i8 %x) { ret i32 %div } +; 17 bits are needed to represent 65535 as a signed value, so this shouldn't fold. + +define i32 @shrink_no3(i16 %x) { +; CHECK-LABEL: @shrink_no3( +; CHECK-NEXT: [[CONV:%.*]] = sext i16 %x to i32 +; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 [[CONV]], 65535 +; CHECK-NEXT: ret i32 [[DIV]] +; + %conv = sext i16 %x to i32 + %div = sdiv i32 %conv, 65535 + ret i32 %div +} + |
