There are some cases where icmp(add) can be folded into a new icmp. Handle them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46687 91177308-0d34-0410-b5e6-96231b3b80d8
2026-04-26 12:20:42 +00:00 · 2008-02-03 16:33:09 +00:00
parent 0c2c3f6e81
commit 5be2920149
2 changed files with 51 additions and 0 deletions
@@ -0,0 +1,19 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep {a.off}
+
+define i1 @test1(i32 %a) {
+  %a.off = add i32 %a, 4          ; <i32> [#uses=1]
+  %C = icmp ult i32 %a.off, 4             ; <i1> [#uses=1]
+  ret i1 %C
+}
+
+define i1 @test2(i32 %a) {
+  %a.off = sub i32 %a, 4          ; <i32> [#uses=1]
+  %C = icmp ugt i32 %a.off, -5             ; <i1> [#uses=1]
+  ret i1 %C
+}
+
+define i1 @test3(i32 %a) {
+  %a.off = add i32 %a, 4          ; <i32> [#uses=1]
+  %C = icmp slt i32 %a.off, 2147483652             ; <i1> [#uses=1]
+  ret i1 %C
+}