give instcombine some helper functions for matching MIN and MAX, and

implement some optimizations for MIN(MIN()) and MAX(MAX()) and 
MIN(MAX()) etc.  This substantially improves the code in PR5822 but
doesn't kick in much elsewhere.  2 max's were optimized in 
pairlocalalign and one in smg2000.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91814 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 40 insertions, 0 deletions

diff --git a/test/Transforms/InstCombine/select.ll b/test/Transforms/InstCombine/select.ll
index 565cfa57ff..7c597007c3 100644
--- a/test/Transforms/InstCombine/select.ll
+++ b/test/Transforms/InstCombine/select.ll
@@ -382,3 +382,43 @@ next:
 ; CHECK-NEXT: ret i32 %a
 }
 
+
+define i32 @test30(i32 %x, i32 %y) {
+  %cmp = icmp sgt i32 %x, %y
+  %cond = select i1 %cmp, i32 %x, i32 %y
+  %cmp5 = icmp sgt i32 %cond, %x
+  %retval = select i1 %cmp5, i32 %cond, i32 %x
+  ret i32 %retval
+}
+
+define i32 @test31(i32 %x, i32 %y) {
+  %cmp = icmp ugt i32 %x, %y 
+  %cond = select i1 %cmp, i32 %x, i32 %y
+  %cmp5 = icmp ugt i32 %cond, %x
+  %retval = select i1 %cmp5, i32 %cond, i32 %x
+  ret i32 %retval
+}
+
+define i32 @test32(i32 %x, i32 %y) {
+  %cmp = icmp sgt i32 %x, %y
+  %cond = select i1 %cmp, i32 %y, i32 %x
+  %cmp5 = icmp sgt i32 %cond, %x
+  %retval = select i1 %cmp5, i32 %x, i32 %cond
+  ret i32 %retval
+}
+
+define i32 @test33(i32 %x, i32 %y) {
+  %cmp = icmp sgt i32 %x, %y
+  %cond = select i1 %cmp, i32 %y, i32 %x
+  %cmp5 = icmp sgt i32 %cond, %x
+  %retval = select i1 %cmp5, i32 %cond, i32 %x
+  ret i32 %retval
+}
+
+define i32 @test34(i32 %x, i32 %y) {
+  %cmp = icmp sgt i32 %x, %y
+  %cond = select i1 %cmp, i32 %x, i32 %y
+  %cmp5 = icmp sgt i32 %cond, %x
+  %retval = select i1 %cmp5, i32 %x, i32 %cond
+  ret i32 %retval
+}