Thread comparisons over udiv/sdiv/ashr/lshr exact and lshr nuw/nsw whenever
possible. This goes into instcombine and instsimplify because instsimplify
doesn't need to check hasOneUse since it returns (almost exclusively) constants.
This fixes PR9343 #4 #5 and #8!
llvm-svn: 127064
diff --git a/llvm/test/Transforms/InstCombine/icmp.ll b/llvm/test/Transforms/InstCombine/icmp.ll
index fb43e59..0230506 100644
--- a/llvm/test/Transforms/InstCombine/icmp.ll
+++ b/llvm/test/Transforms/InstCombine/icmp.ll
@@ -419,3 +419,49 @@
%B = icmp slt i32 %Y, %A
ret i1 %B
}
+
+; CHECK: @test44
+; CHECK: %B = icmp sgt i32 %Y, -1
+define i1 @test44(i32 %X, i32 %Y) {
+ %A = srem i32 %X, %Y
+ %B = icmp slt i32 %A, %Y
+ ret i1 %B
+}
+
+; CHECK: @test45
+; CHECK: %B = icmp slt i32 %Y, 0
+define i1 @test45(i32 %X, i32 %Y) {
+ %A = srem i32 %X, %Y
+ %B = icmp slt i32 %Y, %A
+ ret i1 %B
+}
+
+; PR9343 #4
+; CHECK: @test46
+; CHECK: %C = icmp ult i32 %X, %Y
+define i1 @test46(i32 %X, i32 %Y, i32 %Z) {
+ %A = ashr exact i32 %X, %Z
+ %B = ashr exact i32 %Y, %Z
+ %C = icmp ult i32 %A, %B
+ ret i1 %C
+}
+
+; PR9343 #5
+; CHECK: @test47
+; CHECK: %C = icmp ugt i32 %X, %Y
+define i1 @test47(i32 %X, i32 %Y, i32 %Z) {
+ %A = ashr exact i32 %X, %Z
+ %B = ashr exact i32 %Y, %Z
+ %C = icmp ugt i32 %A, %B
+ ret i1 %C
+}
+
+; PR9343 #8
+; CHECK: @test48
+; CHECK: %C = icmp eq i32 %X, %Y
+define i1 @test48(i32 %X, i32 %Y, i32 %Z) {
+ %A = sdiv exact i32 %X, %Z
+ %B = sdiv exact i32 %Y, %Z
+ %C = icmp eq i32 %A, %B
+ ret i1 %C
+}
diff --git a/llvm/test/Transforms/InstSimplify/compare.ll b/llvm/test/Transforms/InstSimplify/compare.ll
index 7b92de1..7174e7f 100644
--- a/llvm/test/Transforms/InstSimplify/compare.ll
+++ b/llvm/test/Transforms/InstSimplify/compare.ll
@@ -261,6 +261,15 @@
; CHECK: ret i1 true
}
+define i1 @udiv2(i32 %X, i32 %Y, i32 %Z) {
+; CHECK: @udiv2
+ %A = udiv exact i32 10, %Z
+ %B = udiv exact i32 20, %Z
+ %C = icmp ult i32 %A, %B
+ ret i1 %C
+; CHECK: ret i1 true
+}
+
define i1 @sdiv1(i32 %X) {
; CHECK: @sdiv1
%A = sdiv i32 %X, 1000000