1 files changed, 32 insertions, 0 deletions
diff --git a/test/Transforms/InstCombine/preserve-sminmax.ll b/test/Transforms/InstCombine/preserve-sminmax.ll
new file mode 100644
index 0000000..00232cc
--- /dev/null
+++ b/test/Transforms/InstCombine/preserve-sminmax.ll
@@ -0,0 +1,32 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+; Instcombine normally would fold the sdiv into the comparison,
+; making "icmp slt i32 %h, 2", but in this case the sdiv has
+; another use, so it wouldn't a big win, and it would also
+; obfuscate an otherise obvious smax pattern to the point where
+; other analyses wouldn't recognize it.
+
+define i32 @foo(i32 %h) {
+  %sd = sdiv i32 %h, 2
+  %t = icmp slt i32 %sd, 1
+  %r = select i1 %t, i32 %sd, i32 1
+  ret i32 %r
+}
+
+; CHECK:  %sd = sdiv i32 %h, 2
+; CHECK:  %t = icmp slt i32 %sd, 1
+; CHECK:  %r = select i1 %t, i32 %sd, i32 1
+; CHECK:  ret i32 %r
+
+define i32 @bar(i32 %h) {
+  %sd = sdiv i32 %h, 2
+  %t = icmp sgt i32 %sd, 1
+  %r = select i1 %t, i32 %sd, i32 1
+  ret i32 %r
+}
+
+; CHECK:  %sd = sdiv i32 %h, 2
+; CHECK:  %t = icmp sgt i32 %sd, 1
+; CHECK:  %r = select i1 %t, i32 %sd, i32 1
+; CHECK:  ret i32 %r
+