[InstCombine] simplify min/max of min/max with same operands (PR35607)

This is the original integer variant requested in:
https://bugs.llvm.org/show_bug.cgi?id=35607

As noted in the TODO and several similar TODOs around this block,
we could do this in instsimplify, but then it would cost more
because we would be trying to match min/max via ValueTracking
in 2 different places.

There are 4 commuted variants for each of smin/smax/umin/umax
that are not matched here. There are also icmp predicate variants
that are not included in the affected test file because they are
already handled by instsimplify by folding the final icmp to
true/false.

https://rise4fun.com/Alive/3KVc

  Name: smax(smax, smin)
  %c1 = icmp slt i32 %x, %y
  %c2 = icmp slt i32 %y, %x
  %min = select i1 %c1, i32 %x, i32 %y
  %max = select i1 %c2, i32 %x, i32 %y
  %c3 = icmp sgt i32 %max, %min
  %r = select i1 %c3, i32 %max, i32 %min
  =>
  %r = %max

  Name: smin(smax, smin)
  %c1 = icmp slt i32 %x, %y
  %c2 = icmp slt i32 %y, %x
  %min = select i1 %c1, i32 %x, i32 %y
  %max = select i1 %c2, i32 %x, i32 %y
  %c3 = icmp sgt i32 %max, %min
  %r = select i1 %c3, i32 %min, i32 %max
  =>
  %r = %min

  Name: umax(umax, umin)
  %c1 = icmp ult i32 %x, %y
  %c2 = icmp ult i32 %y, %x
  %min = select i1 %c1, i32 %x, i32 %y
  %max = select i1 %c2, i32 %x, i32 %y
  %c3 = icmp ult i32 %min, %max
  %r = select i1 %c3, i32 %max, i32 %min
  =>
  %r = %max

  Name: umin(umax, umin)
  %c1 = icmp ult i32 %x, %y
  %c2 = icmp ult i32 %y, %x
  %min = select i1 %c1, i32 %x, i32 %y
  %max = select i1 %c2, i32 %x, i32 %y
  %c3 = icmp ult i32 %min, %max
  %r = select i1 %c3, i32 %min, i32 %max
  =>
  %r = %min

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369386 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp
index c257cf9e1d035f0ad44738de95562f1c6ed8ea61..2bfd11a2574d21d58aba564203622f5a81b11c94 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -1457,6 +1457,16 @@ Instruction *InstCombiner::foldSPFofSPF(Instruction *Inner,
     }
   }
 
+  // max(max(A, B), min(A, B)) --> max(A, B)
+  // min(min(A, B), max(A, B)) --> min(A, B)
+  // TODO: This could be done in instsimplify.
+  if (SPF1 == SPF2 &&
+      ((SPF1 == SPF_UMIN && match(C, m_c_UMax(m_Specific(A), m_Specific(B)))) ||
+       (SPF1 == SPF_SMIN && match(C, m_c_SMax(m_Specific(A), m_Specific(B)))) ||
+       (SPF1 == SPF_UMAX && match(C, m_c_UMin(m_Specific(A), m_Specific(B)))) ||
+       (SPF1 == SPF_SMAX && match(C, m_c_SMin(m_Specific(A), m_Specific(B))))))
+    return replaceInstUsesWith(Outer, Inner);
+
   // ABS(ABS(X)) -> ABS(X)
   // NABS(NABS(X)) -> NABS(X)
   // TODO: This could be done in instsimplify.

diff --git a/test/Transforms/InstCombine/minmax-of-minmax.ll b/test/Transforms/InstCombine/minmax-of-minmax.ll
index 06a361f6bae5c3f8460f4556844b23ffe5b63659..58f2099e43672a148ad014289f2947e9598148f1 100644 (file)
--- a/test/Transforms/InstCombine/minmax-of-minmax.ll
+++ b/test/Transforms/InstCombine/minmax-of-minmax.ll
@@ -3,13 +3,9 @@
 
 define i32 @smax_of_smax_smin_commute0(i32 %x, i32 %y) {
 ; CHECK-LABEL: @smax_of_smax_smin_commute0(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP1]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 [[Y]], [[X]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 [[Y:%.*]], [[X:%.*]]
 ; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp sgt i32 [[MAX]], [[MIN]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MAX]], i32 [[MIN]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MAX]]
 ;
   %cmp1 = icmp slt i32 %x, %y
   %min = select i1 %cmp1, i32 %x, i32 %y
@@ -22,13 +18,9 @@ define i32 @smax_of_smax_smin_commute0(i32 %x, i32 %y) {
 
 define i32 @smax_of_smax_smin_commute1(i32 %x, i32 %y) {
 ; CHECK-LABEL: @smax_of_smax_smin_commute1(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp sgt i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP1]], i32 [[Y]], i32 [[X]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt i32 [[X]], [[Y]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt i32 [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp sgt i32 [[MAX]], [[MIN]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MAX]], i32 [[MIN]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MAX]]
 ;
   %cmp1 = icmp sgt i32 %x, %y
   %min = select i1 %cmp1, i32 %y, i32 %x
@@ -41,13 +33,9 @@ define i32 @smax_of_smax_smin_commute1(i32 %x, i32 %y) {
 
 define i32 @smax_of_smax_smin_commute2(i32 %x, i32 %y) {
 ; CHECK-LABEL: @smax_of_smax_smin_commute2(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP1]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 [[Y]], [[X]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 [[Y:%.*]], [[X:%.*]]
 ; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp slt i32 [[MIN]], [[MAX]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MAX]], i32 [[MIN]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MAX]]
 ;
   %cmp1 = icmp slt i32 %x, %y
   %min = select i1 %cmp1, i32 %x, i32 %y
@@ -60,13 +48,9 @@ define i32 @smax_of_smax_smin_commute2(i32 %x, i32 %y) {
 
 define <2 x i32> @smax_of_smax_smin_commute3(<2 x i32> %x, <2 x i32> %y) {
 ; CHECK-LABEL: @smax_of_smax_smin_commute3(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp sgt <2 x i32> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MIN:%.*]] = select <2 x i1> [[CMP1]], <2 x i32> [[Y]], <2 x i32> [[X]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt <2 x i32> [[X]], [[Y]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt <2 x i32> [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    [[MAX:%.*]] = select <2 x i1> [[CMP2]], <2 x i32> [[X]], <2 x i32> [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp slt <2 x i32> [[MIN]], [[MAX]]
-; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[CMP3]], <2 x i32> [[MAX]], <2 x i32> [[MIN]]
-; CHECK-NEXT:    ret <2 x i32> [[R]]
+; CHECK-NEXT:    ret <2 x i32> [[MAX]]
 ;
   %cmp1 = icmp sgt <2 x i32> %x, %y
   %min = select <2 x i1> %cmp1, <2 x i32> %y, <2 x i32> %x
@@ -79,13 +63,9 @@ define <2 x i32> @smax_of_smax_smin_commute3(<2 x i32> %x, <2 x i32> %y) {
 
 define i32 @smin_of_smin_smax_commute0(i32 %x, i32 %y) {
 ; CHECK-LABEL: @smin_of_smin_smax_commute0(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp sgt i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP1]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt i32 [[Y]], [[X]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt i32 [[Y:%.*]], [[X:%.*]]
 ; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp sgt i32 [[MAX]], [[MIN]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MIN]], i32 [[MAX]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MIN]]
 ;
   %cmp1 = icmp sgt i32 %x, %y
   %max = select i1 %cmp1, i32 %x, i32 %y
@@ -98,13 +78,9 @@ define i32 @smin_of_smin_smax_commute0(i32 %x, i32 %y) {
 
 define i32 @smin_of_smin_smax_commute1(i32 %x, i32 %y) {
 ; CHECK-LABEL: @smin_of_smin_smax_commute1(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP1]], i32 [[Y]], i32 [[X]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 [[X]], [[Y]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp sgt i32 [[MAX]], [[MIN]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MIN]], i32 [[MAX]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MIN]]
 ;
   %cmp1 = icmp slt i32 %x, %y
   %max = select i1 %cmp1, i32 %y, i32 %x
@@ -117,13 +93,9 @@ define i32 @smin_of_smin_smax_commute1(i32 %x, i32 %y) {
 
 define <2 x i32> @smin_of_smin_smax_commute2(<2 x i32> %x, <2 x i32> %y) {
 ; CHECK-LABEL: @smin_of_smin_smax_commute2(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp sgt <2 x i32> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MAX:%.*]] = select <2 x i1> [[CMP1]], <2 x i32> [[X]], <2 x i32> [[Y]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt <2 x i32> [[X]], [[Y]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt <2 x i32> [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    [[MIN:%.*]] = select <2 x i1> [[CMP2]], <2 x i32> [[X]], <2 x i32> [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp slt <2 x i32> [[MIN]], [[MAX]]
-; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[CMP3]], <2 x i32> [[MIN]], <2 x i32> [[MAX]]
-; CHECK-NEXT:    ret <2 x i32> [[R]]
+; CHECK-NEXT:    ret <2 x i32> [[MIN]]
 ;
   %cmp1 = icmp sgt <2 x i32> %x, %y
   %max = select <2 x i1> %cmp1, <2 x i32> %x, <2 x i32> %y
@@ -136,13 +108,9 @@ define <2 x i32> @smin_of_smin_smax_commute2(<2 x i32> %x, <2 x i32> %y) {
 
 define i32 @smin_of_smin_smax_commute3(i32 %x, i32 %y) {
 ; CHECK-LABEL: @smin_of_smin_smax_commute3(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP1]], i32 [[Y]], i32 [[X]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt i32 [[Y]], [[X]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt i32 [[Y:%.*]], [[X:%.*]]
 ; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp slt i32 [[MIN]], [[MAX]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MIN]], i32 [[MAX]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MIN]]
 ;
   %cmp1 = icmp slt i32 %x, %y
   %max = select i1 %cmp1, i32 %y, i32 %x
@@ -155,13 +123,9 @@ define i32 @smin_of_smin_smax_commute3(i32 %x, i32 %y) {
 
 define i32 @umax_of_umax_umin_commute0(i32 %x, i32 %y) {
 ; CHECK-LABEL: @umax_of_umax_umin_commute0(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP1]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i32 [[Y]], [[X]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i32 [[Y:%.*]], [[X:%.*]]
 ; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp ugt i32 [[MAX]], [[MIN]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MAX]], i32 [[MIN]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MAX]]
 ;
   %cmp1 = icmp ult i32 %x, %y
   %min = select i1 %cmp1, i32 %x, i32 %y
@@ -174,13 +138,9 @@ define i32 @umax_of_umax_umin_commute0(i32 %x, i32 %y) {
 
 define i32 @umax_of_umax_umin_commute1(i32 %x, i32 %y) {
 ; CHECK-LABEL: @umax_of_umax_umin_commute1(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP1]], i32 [[Y]], i32 [[X]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[X]], [[Y]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp ugt i32 [[MAX]], [[MIN]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MAX]], i32 [[MIN]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MAX]]
 ;
   %cmp1 = icmp ugt i32 %x, %y
   %min = select i1 %cmp1, i32 %y, i32 %x
@@ -193,13 +153,9 @@ define i32 @umax_of_umax_umin_commute1(i32 %x, i32 %y) {
 
 define i32 @umax_of_umax_umin_commute2(i32 %x, i32 %y) {
 ; CHECK-LABEL: @umax_of_umax_umin_commute2(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP1]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i32 [[Y]], [[X]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i32 [[Y:%.*]], [[X:%.*]]
 ; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp ult i32 [[MIN]], [[MAX]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MAX]], i32 [[MIN]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MAX]]
 ;
   %cmp1 = icmp ult i32 %x, %y
   %min = select i1 %cmp1, i32 %x, i32 %y
@@ -212,13 +168,9 @@ define i32 @umax_of_umax_umin_commute2(i32 %x, i32 %y) {
 
 define <2 x i32> @umax_of_umax_umin_commute3(<2 x i32> %x, <2 x i32> %y) {
 ; CHECK-LABEL: @umax_of_umax_umin_commute3(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt <2 x i32> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MIN:%.*]] = select <2 x i1> [[CMP1]], <2 x i32> [[Y]], <2 x i32> [[X]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt <2 x i32> [[X]], [[Y]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt <2 x i32> [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    [[MAX:%.*]] = select <2 x i1> [[CMP2]], <2 x i32> [[X]], <2 x i32> [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp ult <2 x i32> [[MIN]], [[MAX]]
-; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[CMP3]], <2 x i32> [[MAX]], <2 x i32> [[MIN]]
-; CHECK-NEXT:    ret <2 x i32> [[R]]
+; CHECK-NEXT:    ret <2 x i32> [[MAX]]
 ;
   %cmp1 = icmp ugt <2 x i32> %x, %y
   %min = select <2 x i1> %cmp1, <2 x i32> %y, <2 x i32> %x
@@ -231,13 +183,9 @@ define <2 x i32> @umax_of_umax_umin_commute3(<2 x i32> %x, <2 x i32> %y) {
 
 define i32 @umin_of_umin_umax_commute0(i32 %x, i32 %y) {
 ; CHECK-LABEL: @umin_of_umin_umax_commute0(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP1]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[Y]], [[X]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[Y:%.*]], [[X:%.*]]
 ; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp ugt i32 [[MAX]], [[MIN]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MIN]], i32 [[MAX]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MIN]]
 ;
   %cmp1 = icmp ugt i32 %x, %y
   %max = select i1 %cmp1, i32 %x, i32 %y
@@ -250,13 +198,9 @@ define i32 @umin_of_umin_umax_commute0(i32 %x, i32 %y) {
 
 define i32 @umin_of_umin_umax_commute1(i32 %x, i32 %y) {
 ; CHECK-LABEL: @umin_of_umin_umax_commute1(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP1]], i32 [[Y]], i32 [[X]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i32 [[X]], [[Y]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i32 [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp ugt i32 [[MAX]], [[MIN]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MIN]], i32 [[MAX]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MIN]]
 ;
   %cmp1 = icmp ult i32 %x, %y
   %max = select i1 %cmp1, i32 %y, i32 %x
@@ -269,13 +213,9 @@ define i32 @umin_of_umin_umax_commute1(i32 %x, i32 %y) {
 
 define <2 x i32> @umin_of_umin_umax_commute2(<2 x i32> %x, <2 x i32> %y) {
 ; CHECK-LABEL: @umin_of_umin_umax_commute2(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt <2 x i32> [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MAX:%.*]] = select <2 x i1> [[CMP1]], <2 x i32> [[X]], <2 x i32> [[Y]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult <2 x i32> [[X]], [[Y]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult <2 x i32> [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    [[MIN:%.*]] = select <2 x i1> [[CMP2]], <2 x i32> [[X]], <2 x i32> [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp ult <2 x i32> [[MIN]], [[MAX]]
-; CHECK-NEXT:    [[R:%.*]] = select <2 x i1> [[CMP3]], <2 x i32> [[MIN]], <2 x i32> [[MAX]]
-; CHECK-NEXT:    ret <2 x i32> [[R]]
+; CHECK-NEXT:    ret <2 x i32> [[MIN]]
 ;
   %cmp1 = icmp ugt <2 x i32> %x, %y
   %max = select <2 x i1> %cmp1, <2 x i32> %x, <2 x i32> %y
@@ -288,13 +228,9 @@ define <2 x i32> @umin_of_umin_umax_commute2(<2 x i32> %x, <2 x i32> %y) {
 
 define i32 @umin_of_umin_umax_commute3(i32 %x, i32 %y) {
 ; CHECK-LABEL: @umin_of_umin_umax_commute3(
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i32 [[X:%.*]], [[Y:%.*]]
-; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP1]], i32 [[Y]], i32 [[X]]
-; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[Y]], [[X]]
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[Y:%.*]], [[X:%.*]]
 ; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 [[Y]]
-; CHECK-NEXT:    [[CMP3:%.*]] = icmp ult i32 [[MIN]], [[MAX]]
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP3]], i32 [[MIN]], i32 [[MAX]]
-; CHECK-NEXT:    ret i32 [[R]]
+; CHECK-NEXT:    ret i32 [[MIN]]
 ;
   %cmp1 = icmp ult i32 %x, %y
   %max = select i1 %cmp1, i32 %y, i32 %x
@@ -305,6 +241,8 @@ define i32 @umin_of_umin_umax_commute3(i32 %x, i32 %y) {
   ret i32 %r
 }
 
+; Negative test - mismatch of min/max flavor
+
 define i32 @umin_of_smin_umax_wrong_pattern(i32 %x, i32 %y) {
 ; CHECK-LABEL: @umin_of_smin_umax_wrong_pattern(
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i32 [[X:%.*]], [[Y:%.*]]
@@ -324,6 +262,8 @@ define i32 @umin_of_smin_umax_wrong_pattern(i32 %x, i32 %y) {
   ret i32 %r
 }
 
+; Negative test - mismatch of min/max flavor
+
 define i32 @smin_of_umin_umax_wrong_pattern2(i32 %x, i32 %y) {
 ; CHECK-LABEL: @smin_of_umin_umax_wrong_pattern2(
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i32 [[X:%.*]], [[Y:%.*]]
@@ -343,6 +283,8 @@ define i32 @smin_of_umin_umax_wrong_pattern2(i32 %x, i32 %y) {
   ret i32 %r
 }
 
+; Negative test - operands must match
+
 define <2 x i32> @umin_of_umin_umax_wrong_operand(<2 x i32> %x, <2 x i32> %y, <2 x i32> %z) {
 ; CHECK-LABEL: @umin_of_umin_umax_wrong_operand(
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt <2 x i32> [[X:%.*]], [[Y:%.*]]
@@ -362,6 +304,8 @@ define <2 x i32> @umin_of_umin_umax_wrong_operand(<2 x i32> %x, <2 x i32> %y, <2
   ret <2 x i32> %r
 }
 
+; Negative test - operands must match
+
 define i32 @umin_of_umin_umax_wrong_operand2(i32 %x, i32 %y, i32 %z) {
 ; CHECK-LABEL: @umin_of_umin_umax_wrong_operand2(
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i32 [[X:%.*]], [[Z:%.*]]