[llvm] 1008435 - Revert "[InstCombine] do not exclude min/max from icmp with casted operand fold"

Sanjay Patel via llvm-commits llvm-commits at lists.llvm.org
Thu Apr 2 06:32:24 PDT 2020


Author: Sanjay Patel
Date: 2020-04-02T09:15:23-04:00
New Revision: 1008435f3d47ac0f49690c52cb8ae3af6e3b9c4b

URL: https://github.com/llvm/llvm-project/commit/1008435f3d47ac0f49690c52cb8ae3af6e3b9c4b
DIFF: https://github.com/llvm/llvm-project/commit/1008435f3d47ac0f49690c52cb8ae3af6e3b9c4b.diff

LOG: Revert "[InstCombine] do not exclude min/max from icmp with casted operand fold"

This reverts commit f2fbdf76d8d07f6a0fbd97825cbc533660d64a37.
As noted in the post-commit thread:
https://reviews.llvm.org/rGf2fbdf76d8d0
...this can obscure a min/max pattern where the components
have extra uses. We can show that the problem is independent
of this change with a slightly modified source example, so
this revert just delays/reduces the need to fix the real
problem.

We need to improve our analysis of negation or -- more
generally -- subtraction using patches like D77230 or D68408.

Added: 
    

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
    llvm/test/Transforms/InstCombine/adjust-for-minmax.ll
    llvm/test/Transforms/InstCombine/select_meta.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index e2c53ae0b31d..93312d4f97d8 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -5503,9 +5503,6 @@ 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;
 
@@ -5585,6 +5582,9 @@ 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 478e94eedb19..9a5b1f5d5a0a 100644
--- 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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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:    [[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:    [[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:    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 c76e8e1e14ca..67dd246c0408 100644
--- a/llvm/test/Transforms/InstCombine/select_meta.ll
+++ b/llvm/test/Transforms/InstCombine/select_meta.ll
@@ -66,9 +66,9 @@ define i32 @foo2(i32, i32) local_unnamed_addr #0  {
 
 define i64 @test43(i32 %a) nounwind {
 ; CHECK-LABEL: @test43(
-; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt i32 [[A:%.*]], 0
-; CHECK-NEXT:    [[NARROW:%.*]] = select i1 [[TMP1]], i32 [[A]], i32 0, !prof ![[$MD1]]
-; CHECK-NEXT:    [[MAX:%.*]] = zext i32 [[NARROW]] to i64
+; CHECK-NEXT:    [[A_EXT:%.*]] = sext i32 %a to i64
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt i64 [[A_EXT]], 0
+; CHECK-NEXT:    [[MAX:%.*]] = select i1 [[TMP1]], i64 [[A_EXT]], i64 0, !prof ![[$MD1]]
 ; CHECK-NEXT:    ret i64 [[MAX]]
 ;
   %a_ext = sext i32 %a to i64


        


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