From 143ffebf675fe0d90b55d2226c6f690fc4b7ed4b Mon Sep 17 00:00:00 2001
From: Sanjay Patel <spatel@rotateright.com>
Date: Wed, 11 Oct 2017 14:29:17 +0000
Subject: [PATCH] [InstCombine] add baseline tests for D38531; NFC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315461 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Transforms/InstCombine/minmax-fold.ll | 104 ++++++++++++++++++++-
 1 file changed, 103 insertions(+), 1 deletion(-)

diff --git a/test/Transforms/InstCombine/minmax-fold.ll b/test/Transforms/InstCombine/minmax-fold.ll
index 568fd50fd69..5197a58ef8b 100644
--- a/test/Transforms/InstCombine/minmax-fold.ll
+++ b/test/Transforms/InstCombine/minmax-fold.ll
@@ -361,7 +361,7 @@ define i32 @test75(i32 %x) {
   ret i32 %retval
 }
 
-; The next 4 tests are value clamping with constants:
+; The next 10 tests are value clamping with constants:
 ; https://llvm.org/bugs/show_bug.cgi?id=31693
 
 ; (X <s C1) ? C1 : SMIN(X, C2) ==> SMAX(SMIN(X, C2), C1)
@@ -398,6 +398,40 @@ define i32 @clamp_signed2(i32 %x) {
   ret i32 %r
 }
 
+; (X >s C1) ? SMIN(X, C2) : C1 ==> SMAX(SMIN(X, C2), C1)
+
+define i32 @clamp_signed3(i32 %x) {
+; CHECK-LABEL: @clamp_signed3(
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 [[X:%.*]], 255
+; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 255
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp sgt i32 [[X]], 15
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP1]], i32 [[MIN]], i32 15
+; CHECK-NEXT:    ret i32 [[R]]
+;
+  %cmp2 = icmp slt i32 %x, 255
+  %min = select i1 %cmp2, i32 %x, i32 255
+  %cmp1 = icmp sgt i32 %x, 15
+  %r = select i1 %cmp1, i32 %min, i32 15
+  ret i32 %r
+}
+
+; (X <s C1) ? SMAX(X, C2) : C1 ==> SMIN(SMAX(X, C1), C2)
+
+define i32 @clamp_signed4(i32 %x) {
+; CHECK-LABEL: @clamp_signed4(
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp sgt i32 [[X:%.*]], 15
+; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 15
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i32 [[X]], 255
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP1]], i32 [[MAX]], i32 255
+; CHECK-NEXT:    ret i32 [[R]]
+;
+  %cmp2 = icmp sgt i32 %x, 15
+  %max = select i1 %cmp2, i32 %x, i32 15
+  %cmp1 = icmp slt i32 %x, 255
+  %r = select i1 %cmp1, i32 %max, i32 255
+  ret i32 %r
+}
+
 ; (X <u C1) ? C1 : UMIN(X, C2) ==> UMAX(UMIN(X, C2), C1)
 
 define i32 @clamp_unsigned1(i32 %x) {
@@ -432,6 +466,74 @@ define i32 @clamp_unsigned2(i32 %x) {
   ret i32 %r
 }
 
+; (X >u C1) ? UMIN(X, C2) : C1 ==> UMAX(UMIN(X, C2), C1)
+
+define i32 @clamp_unsigned3(i32 %x) {
+; CHECK-LABEL: @clamp_unsigned3(
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i32 [[X:%.*]], 255
+; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 255
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i32 [[X]], 15
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP1]], i32 [[MIN]], i32 15
+; CHECK-NEXT:    ret i32 [[R]]
+;
+  %cmp2 = icmp ult i32 %x, 255
+  %min = select i1 %cmp2, i32 %x, i32 255
+  %cmp1 = icmp ugt i32 %x, 15
+  %r = select i1 %cmp1, i32 %min, i32 15
+  ret i32 %r
+}
+
+; (X <u C1) ? UMAX(X, C2) : C1 ==> UMIN(UMAX(X, C2), C1)
+
+define i32 @clamp_unsigned4(i32 %x) {
+; CHECK-LABEL: @clamp_unsigned4(
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[X:%.*]], 15
+; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[CMP2]], i32 [[X]], i32 15
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i32 [[X]], 255
+; CHECK-NEXT:    [[R:%.*]] = select i1 [[CMP1]], i32 [[MAX]], i32 255
+; CHECK-NEXT:    ret i32 [[R]]
+;
+  %cmp2 = icmp ugt i32 %x, 15
+  %max = select i1 %cmp2, i32 %x, i32 15
+  %cmp1 = icmp ult i32 %x, 255
+  %r = select i1 %cmp1, i32 %max, i32 255
+  ret i32 %r
+}
+
+; Check that clamp is recognized and there is no infinite
+; loop because of reverse cmp transformation:
+; (icmp sgt smin(PositiveA, B) 0) -> (icmp sgt B 0)
+define i32 @clamp_check_for_no_infinite_loop1(i32 %i) {
+; CHECK-LABEL: @clamp_check_for_no_infinite_loop1(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i32 [[I:%.*]], 255
+; CHECK-NEXT:    [[SEL1:%.*]] = select i1 [[CMP1]], i32 [[I]], i32 255
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt i32 [[I]], 0
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[TMP1]], i32 [[SEL1]], i32 0
+; CHECK-NEXT:    ret i32 [[RES]]
+;
+  %cmp1 = icmp slt i32 %i, 255
+  %sel1 = select i1 %cmp1, i32 %i, i32 255
+  %cmp2 = icmp slt i32 %i, 0
+  %res = select i1 %cmp2, i32 0, i32 %sel1
+  ret i32 %res
+}
+; Check that there is no infinite loop in case of:
+; (icmp slt smax(NegativeA, B) 0) -> (icmp slt B 0)
+define i32 @clamp_check_for_no_infinite_loop2(i32 %i) {
+; CHECK-LABEL: @clamp_check_for_no_infinite_loop2(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp sgt i32 [[I:%.*]], -255
+; CHECK-NEXT:    [[SEL1:%.*]] = select i1 [[CMP1]], i32 [[I]], i32 -255
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 [[I]], 0
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[CMP2]], i32 [[SEL1]], i32 0
+; CHECK-NEXT:    ret i32 [[RES]]
+;
+  %cmp1 = icmp sgt i32 %i, -255
+  %sel1 = select i1 %cmp1, i32 %i, i32 -255
+  %cmp2 = icmp slt i32 %i, 0
+  %res = select i1 %cmp2, i32 %sel1, i32 0
+  ret i32 %res
+}
+
 ; The next 3 min tests should canonicalize to the same form...and not infinite loop.
 
 define double @PR31751_umin1(i32 %x) {
-- 
2.40.0