Handle some more combinations of extend and icmp. Fixes PR1940.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46431 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/InstCombine/2008-01-21-MismatchedCastAndCompare.ll

@@ -0,0 +1,17 @@
+; RUN: llvm-as < %s | opt -instcombine | notcast
+; RUN: llvm-as < %s | opt -instcombine | not grep {icmp s}
+; PR1940
+
+define i1 @test1(i8 %A, i8 %B) {
+        %a = zext i8 %A to i32
+        %b = zext i8 %B to i32
+        %c = icmp sgt i32 %a, %b
+        ret i1 %c
+}
+
+define i1 @test2(i8 %A, i8 %B) {
+        %a = sext i8 %A to i32
+        %b = sext i8 %B to i32
+        %c = icmp ugt i32 %a, %b
+        ret i1 %c
+}