Look pass zext to strength reduce an udiv. Patch by David Majnemer. rdar://11721329

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158946 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 23 insertions, 9 deletions

diff --git a/test/Transforms/InstCombine/div-shift.ll b/test/Transforms/InstCombine/div-shift.ll
new file mode 100644
index 0000000..a07f3ea
--- /dev/null
+++ b/test/Transforms/InstCombine/div-shift.ll
@@ -0,0 +1,23 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+define i32 @t1(i16 zeroext %x, i32 %y) nounwind {
+entry:
+; CHECK: t1
+; CHECK-NOT: sdiv
+; CHECK: lshr i32 %conv
+  %conv = zext i16 %x to i32
+  %s = shl i32 2, %y
+  %d = sdiv i32 %conv, %s
+  ret i32 %d
+}
+
+; rdar://11721329
+define i64 @t2(i64 %x, i32 %y) nounwind  {
+; CHECK: t2
+; CHECK-NOT: udiv
+; CHECK: lshr i64 %x
+  %1 = shl i32 1, %y
+  %2 = zext i32 %1 to i64
+  %3 = udiv i64 %x, %2
+  ret i64 %3
+}
diff --git a/test/Transforms/InstCombine/sdiv-shift.ll b/test/Transforms/InstCombine/sdiv-shift.ll
deleted file mode 100644
index f4d2b36..0000000
--- a/test/Transforms/InstCombine/sdiv-shift.ll
+++ /dev/null
@@ -1,9 +0,0 @@
-; RUN: opt < %s -instcombine -S | not grep div
-
-define i32 @a(i16 zeroext %x, i32 %y) nounwind {
-entry:
-	%conv = zext i16 %x to i32
-	%s = shl i32 2, %y
-	%d = sdiv i32 %conv, %s
-	ret i32 %d
-}