[InstCombine] do not exclude min/max from icmp with casted operand fold

InstCombine has a mess of logic that tries to preserve min/max patterns,
but AFAICT, this one is not necessary because we can always narrow the
corresponding select in this sequence to match the narrow compare.

The biggest danger for this patch is inducing infinite looping or
assert from exceeding max iterations. If any bots hit that in the
vicinity of this commit, this is the likely patch to blame.

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 31dfd46..c8276c7 100644 (file)
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -5503,6 +5503,9 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
   if (Instruction *Res = foldICmpBinOp(I, Q))
     return Res;
 
+  if (Instruction *R = foldICmpWithCastOp(I))
+    return R;
+
   if (Instruction *Res = foldICmpUsingKnownBits(I))
     return Res;
 
@@ -5582,9 +5585,6 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
   if (Instruction *Res = foldICmpBitCast(I, Builder))
     return Res;
 
-  if (Instruction *R = foldICmpWithCastOp(I))
-    return R;
-
   if (Instruction *Res = foldICmpWithMinMax(I))
     return Res;
 

diff --git a/llvm/test/Transforms/InstCombine/adjust-for-minmax.ll b/llvm/test/Transforms/InstCombine/adjust-for-minmax.ll
index 9a5b1f5..478e94e 100644 (file)
--- a/llvm/test/Transforms/InstCombine/adjust-for-minmax.ll
+++ b/llvm/test/Transforms/InstCombine/adjust-for-minmax.ll
@@ -265,9 +265,9 @@ define <2 x i32> @umin4_vec(<2 x i32> %n) {
 
 define i64 @smax_sext(i32 %a) {
 ; CHECK-LABEL: @smax_sext(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext i32 [[A:%.*]] to i64
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt i64 [[A_EXT]], 0
-; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[TMP1]], i64 [[A_EXT]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt i32 [[A:%.*]], 0
+; CHECK-NEXT:    [[NARROW:%.*]] = select i1 [[TMP1]], i32 [[A]], i32 0
+; CHECK-NEXT:    [[MAX:%.*]] = zext i32 [[NARROW]] to i64
 ; CHECK-NEXT:    ret i64 [[MAX]]
 ;
   %a_ext = sext i32 %a to i64
@@ -278,9 +278,9 @@ define i64 @smax_sext(i32 %a) {
 
 define <2 x i64> @smax_sext_vec(<2 x i32> %a) {
 ; CHECK-LABEL: @smax_sext_vec(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext <2 x i32> [[A:%.*]] to <2 x i64>
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt <2 x i64> [[A_EXT]], zeroinitializer
-; CHECK-NEXT:    [[MAX:%.*]] = select <2 x i1> [[TMP1]], <2 x i64> [[A_EXT]], <2 x i64> zeroinitializer
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt <2 x i32> [[A:%.*]], zeroinitializer
+; CHECK-NEXT:    [[NARROW:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[A]], <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[MAX:%.*]] = zext <2 x i32> [[NARROW]] to <2 x i64>
 ; CHECK-NEXT:    ret <2 x i64> [[MAX]]
 ;
   %a_ext = sext <2 x i32> %a to <2 x i64>
@@ -291,9 +291,9 @@ define <2 x i64> @smax_sext_vec(<2 x i32> %a) {
 
 define i64 @smin_sext(i32 %a) {
 ; CHECK-LABEL: @smin_sext(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext i32 [[A:%.*]] to i64
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i64 [[A_EXT]], 0
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[TMP1]], i64 [[A_EXT]], i64 0
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt i32 [[A:%.*]], 0
+; CHECK-NEXT:    [[NARROW:%.*]] = select i1 [[TMP1]], i32 [[A]], i32 0
+; CHECK-NEXT:    [[MIN:%.*]] = sext i32 [[NARROW]] to i64
 ; CHECK-NEXT:    ret i64 [[MIN]]
 ;
   %a_ext = sext i32 %a to i64
@@ -304,9 +304,9 @@ define i64 @smin_sext(i32 %a) {
 
 define <2 x i64>@smin_sext_vec(<2 x i32> %a) {
 ; CHECK-LABEL: @smin_sext_vec(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext <2 x i32> [[A:%.*]] to <2 x i64>
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i64> [[A_EXT]], zeroinitializer
-; CHECK-NEXT:    [[MIN:%.*]] = select <2 x i1> [[TMP1]], <2 x i64> [[A_EXT]], <2 x i64> zeroinitializer
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i32> [[A:%.*]], zeroinitializer
+; CHECK-NEXT:    [[NARROW:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[A]], <2 x i32> zeroinitializer
+; CHECK-NEXT:    [[MIN:%.*]] = sext <2 x i32> [[NARROW]] to <2 x i64>
 ; CHECK-NEXT:    ret <2 x i64> [[MIN]]
 ;
   %a_ext = sext <2 x i32> %a to <2 x i64>
@@ -317,9 +317,9 @@ define <2 x i64>@smin_sext_vec(<2 x i32> %a) {
 
 define i64 @umax_sext(i32 %a) {
 ; CHECK-LABEL: @umax_sext(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext i32 [[A:%.*]] to i64
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt i64 [[A_EXT]], 3
-; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[TMP1]], i64 [[A_EXT]], i64 3
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt i32 [[A:%.*]], 3
+; CHECK-NEXT:    [[NARROW:%.*]] = select i1 [[TMP1]], i32 [[A]], i32 3
+; CHECK-NEXT:    [[MAX:%.*]] = sext i32 [[NARROW]] to i64
 ; CHECK-NEXT:    ret i64 [[MAX]]
 ;
   %a_ext = sext i32 %a to i64
@@ -330,9 +330,9 @@ define i64 @umax_sext(i32 %a) {
 
 define <2 x i64> @umax_sext_vec(<2 x i32> %a) {
 ; CHECK-LABEL: @umax_sext_vec(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext <2 x i32> [[A:%.*]] to <2 x i64>
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt <2 x i64> [[A_EXT]], <i64 3, i64 3>
-; CHECK-NEXT:    [[MAX:%.*]] = select <2 x i1> [[TMP1]], <2 x i64> [[A_EXT]], <2 x i64> <i64 3, i64 3>
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt <2 x i32> [[A:%.*]], <i32 3, i32 3>
+; CHECK-NEXT:    [[NARROW:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[A]], <2 x i32> <i32 3, i32 3>
+; CHECK-NEXT:    [[MAX:%.*]] = sext <2 x i32> [[NARROW]] to <2 x i64>
 ; CHECK-NEXT:    ret <2 x i64> [[MAX]]
 ;
   %a_ext = sext <2 x i32> %a to <2 x i64>
@@ -343,9 +343,9 @@ define <2 x i64> @umax_sext_vec(<2 x i32> %a) {
 
 define i64 @umin_sext(i32 %a) {
 ; CHECK-LABEL: @umin_sext(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext i32 [[A:%.*]] to i64
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 [[A_EXT]], 2
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[TMP1]], i64 [[A_EXT]], i64 2
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i32 [[A:%.*]], 2
+; CHECK-NEXT:    [[NARROW:%.*]] = select i1 [[TMP1]], i32 [[A]], i32 2
+; CHECK-NEXT:    [[MIN:%.*]] = zext i32 [[NARROW]] to i64
 ; CHECK-NEXT:    ret i64 [[MIN]]
 ;
   %a_ext = sext i32 %a to i64
@@ -356,9 +356,9 @@ define i64 @umin_sext(i32 %a) {
 
 define <2 x i64> @umin_sext_vec(<2 x i32> %a) {
 ; CHECK-LABEL: @umin_sext_vec(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext <2 x i32> [[A:%.*]] to <2 x i64>
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult <2 x i64> [[A_EXT]], <i64 2, i64 2>
-; CHECK-NEXT:    [[MIN:%.*]] = select <2 x i1> [[TMP1]], <2 x i64> [[A_EXT]], <2 x i64> <i64 2, i64 2>
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult <2 x i32> [[A:%.*]], <i32 2, i32 2>
+; CHECK-NEXT:    [[NARROW:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[A]], <2 x i32> <i32 2, i32 2>
+; CHECK-NEXT:    [[MIN:%.*]] = zext <2 x i32> [[NARROW]] to <2 x i64>
 ; CHECK-NEXT:    ret <2 x i64> [[MIN]]
 ;
   %a_ext = sext <2 x i32> %a to <2 x i64>
@@ -369,9 +369,9 @@ define <2 x i64> @umin_sext_vec(<2 x i32> %a) {
 
 define i64 @umax_sext2(i32 %a) {
 ; CHECK-LABEL: @umax_sext2(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext i32 [[A:%.*]] to i64
-; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i64 [[A_EXT]], 2
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP]], i64 [[A_EXT]], i64 2
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i32 [[A:%.*]], 2
+; CHECK-NEXT:    [[NARROW:%.*]] = select i1 [[CMP]], i32 [[A]], i32 2
+; CHECK-NEXT:    [[MIN:%.*]] = sext i32 [[NARROW]] to i64
 ; CHECK-NEXT:    ret i64 [[MIN]]
 ;
   %a_ext = sext i32 %a to i64
@@ -382,9 +382,9 @@ define i64 @umax_sext2(i32 %a) {
 
 define <2 x i64> @umax_sext2_vec(<2 x i32> %a) {
 ; CHECK-LABEL: @umax_sext2_vec(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext <2 x i32> [[A:%.*]] to <2 x i64>
-; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt <2 x i64> [[A_EXT]], <i64 2, i64 2>
-; CHECK-NEXT:    [[MIN:%.*]] = select <2 x i1> [[CMP]], <2 x i64> [[A_EXT]], <2 x i64> <i64 2, i64 2>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt <2 x i32> [[A:%.*]], <i32 2, i32 2>
+; CHECK-NEXT:    [[NARROW:%.*]] = select <2 x i1> [[CMP]], <2 x i32> [[A]], <2 x i32> <i32 2, i32 2>
+; CHECK-NEXT:    [[MIN:%.*]] = sext <2 x i32> [[NARROW]] to <2 x i64>
 ; CHECK-NEXT:    ret <2 x i64> [[MIN]]
 ;
   %a_ext = sext <2 x i32> %a to <2 x i64>
@@ -395,9 +395,9 @@ define <2 x i64> @umax_sext2_vec(<2 x i32> %a) {
 
 define i64 @umin_sext2(i32 %a) {
 ; CHECK-LABEL: @umin_sext2(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext i32 [[A:%.*]] to i64
-; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i64 [[A_EXT]], 3
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[CMP]], i64 [[A_EXT]], i64 3
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[A:%.*]], 3
+; CHECK-NEXT:    [[NARROW:%.*]] = select i1 [[CMP]], i32 [[A]], i32 3
+; CHECK-NEXT:    [[MIN:%.*]] = zext i32 [[NARROW]] to i64
 ; CHECK-NEXT:    ret i64 [[MIN]]
 ;
   %a_ext = sext i32 %a to i64
@@ -408,9 +408,9 @@ define i64 @umin_sext2(i32 %a) {
 
 define <2 x i64> @umin_sext2_vec(<2 x i32> %a) {
 ; CHECK-LABEL: @umin_sext2_vec(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext <2 x i32> [[A:%.*]] to <2 x i64>
-; CHECK-NEXT:    [[CMP:%.*]] = icmp ult <2 x i64> [[A_EXT]], <i64 3, i64 3>
-; CHECK-NEXT:    [[MIN:%.*]] = select <2 x i1> [[CMP]], <2 x i64> [[A_EXT]], <2 x i64> <i64 3, i64 3>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult <2 x i32> [[A:%.*]], <i32 3, i32 3>
+; CHECK-NEXT:    [[NARROW:%.*]] = select <2 x i1> [[CMP]], <2 x i32> [[A]], <2 x i32> <i32 3, i32 3>
+; CHECK-NEXT:    [[MIN:%.*]] = zext <2 x i32> [[NARROW]] to <2 x i64>
 ; CHECK-NEXT:    ret <2 x i64> [[MIN]]
 ;
   %a_ext = sext <2 x i32> %a to <2 x i64>
@@ -421,9 +421,9 @@ define <2 x i64> @umin_sext2_vec(<2 x i32> %a) {
 
 define i64 @umax_zext(i32 %a) {
 ; CHECK-LABEL: @umax_zext(
-; CHECK-NEXT:    [[A_EXT:%.*]] = zext i32 [[A:%.*]] to i64
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt i64 [[A_EXT]], 3
-; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[TMP1]], i64 [[A_EXT]], i64 3
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt i32 [[A:%.*]], 3
+; CHECK-NEXT:    [[NARROW:%.*]] = select i1 [[TMP1]], i32 [[A]], i32 3
+; CHECK-NEXT:    [[MAX:%.*]] = zext i32 [[NARROW]] to i64
 ; CHECK-NEXT:    ret i64 [[MAX]]
 ;
   %a_ext = zext i32 %a to i64
@@ -434,9 +434,9 @@ define i64 @umax_zext(i32 %a) {
 
 define <2 x i64> @umax_zext_vec(<2 x i32> %a) {
 ; CHECK-LABEL: @umax_zext_vec(
-; CHECK-NEXT:    [[A_EXT:%.*]] = zext <2 x i32> [[A:%.*]] to <2 x i64>
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt <2 x i64> [[A_EXT]], <i64 3, i64 3>
-; CHECK-NEXT:    [[MAX:%.*]] = select <2 x i1> [[TMP1]], <2 x i64> [[A_EXT]], <2 x i64> <i64 3, i64 3>
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ugt <2 x i32> [[A:%.*]], <i32 3, i32 3>
+; CHECK-NEXT:    [[NARROW:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[A]], <2 x i32> <i32 3, i32 3>
+; CHECK-NEXT:    [[MAX:%.*]] = zext <2 x i32> [[NARROW]] to <2 x i64>
 ; CHECK-NEXT:    ret <2 x i64> [[MAX]]
 ;
   %a_ext = zext <2 x i32> %a to <2 x i64>
@@ -447,9 +447,9 @@ define <2 x i64> @umax_zext_vec(<2 x i32> %a) {
 
 define i64 @umin_zext(i32 %a) {
 ; CHECK-LABEL: @umin_zext(
-; CHECK-NEXT:    [[A_EXT:%.*]] = zext i32 [[A:%.*]] to i64
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i64 [[A_EXT]], 2
-; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[TMP1]], i64 [[A_EXT]], i64 2
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i32 [[A:%.*]], 2
+; CHECK-NEXT:    [[NARROW:%.*]] = select i1 [[TMP1]], i32 [[A]], i32 2
+; CHECK-NEXT:    [[MIN:%.*]] = zext i32 [[NARROW]] to i64
 ; CHECK-NEXT:    ret i64 [[MIN]]
 ;
   %a_ext = zext i32 %a to i64
@@ -460,9 +460,9 @@ define i64 @umin_zext(i32 %a) {
 
 define <2 x i64> @umin_zext_vec(<2 x i32> %a) {
 ; CHECK-LABEL: @umin_zext_vec(
-; CHECK-NEXT:    [[A_EXT:%.*]] = zext <2 x i32> [[A:%.*]] to <2 x i64>
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult <2 x i64> [[A_EXT]], <i64 2, i64 2>
-; CHECK-NEXT:    [[MIN:%.*]] = select <2 x i1> [[TMP1]], <2 x i64> [[A_EXT]], <2 x i64> <i64 2, i64 2>
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult <2 x i32> [[A:%.*]], <i32 2, i32 2>
+; CHECK-NEXT:    [[NARROW:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[A]], <2 x i32> <i32 2, i32 2>
+; CHECK-NEXT:    [[MIN:%.*]] = zext <2 x i32> [[NARROW]] to <2 x i64>
 ; CHECK-NEXT:    ret <2 x i64> [[MIN]]
 ;
   %a_ext = zext <2 x i32> %a to <2 x i64>

diff --git a/llvm/test/Transforms/InstCombine/select_meta.ll b/llvm/test/Transforms/InstCombine/select_meta.ll
index 67dd246..e05883a 100644 (file)
--- a/llvm/test/Transforms/InstCombine/select_meta.ll
+++ b/llvm/test/Transforms/InstCombine/select_meta.ll
@@ -1,4 +1,4 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function test43
 ; and enhanced to include metadata checking.
 
 ; RUN: opt < %s -instcombine -S | FileCheck %s
@@ -66,9 +66,9 @@ define i32 @foo2(i32, i32) local_unnamed_addr #0  {
 
 define i64 @test43(i32 %a) nounwind {
 ; CHECK-LABEL: @test43(
-; CHECK-NEXT:    [[A_EXT:%.*]] = sext i32 %a to i64
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt i64 [[A_EXT]], 0
-; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[TMP1]], i64 [[A_EXT]], i64 0, !prof ![[$MD1]]
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt i32 [[A:%.*]], 0
+; CHECK-NEXT:    [[NARROW:%.*]] = select i1 [[TMP1]], i32 [[A]], i32 0, !prof ![[$MD1]]
+; CHECK-NEXT:    [[MAX:%.*]] = zext i32 [[NARROW]] to i64
 ; CHECK-NEXT:    ret i64 [[MAX]]
 ;
   %a_ext = sext i32 %a to i64