[llvm] 054b1b3 - Revert "[SLP]Fix final analysis for unsigned nodes."

[Mikhail Goncharov via llvm-commits]

Author: Mikhail Goncharov
Date: 2024-04-19T11:32:56+02:00
New Revision: 054b1b3b5ac67385220654df12732346b51c8a41

URL: https://github.com/llvm/llvm-project/commit/054b1b3b5ac67385220654df12732346b51c8a41
DIFF: https://github.com/llvm/llvm-project/commit/054b1b3b5ac67385220654df12732346b51c8a41.diff

LOG: Revert "[SLP]Fix final analysis for unsigned nodes."

This reverts commit 74e07ab523122d6a8347b25770062ab331b6bb84.

It might be that Mask.getBitWidth() == Mask.countl_zero() (32 in my
case) and zero bitwidth2 causes the crash.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
    llvm/test/Transforms/SLPVectorizer/RISCV/unsigned-node-trunc-with-signed-users.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 25cb6bb599831a..075fbd3bf868f1 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -14442,18 +14442,11 @@ bool BoUpSLP::collectValuesToDemote(
     }
     auto NumSignBits = ComputeNumSignBits(V, *DL, 0, AC, nullptr, DT);
     unsigned BitWidth1 = OrigBitWidth - NumSignBits;
-    bool IsSigned = !isKnownNonNegative(V, SimplifyQuery(*DL));
-    if (IsSigned)
+    if (!isKnownNonNegative(V, SimplifyQuery(*DL)))
       ++BitWidth1;
     if (auto *I = dyn_cast<Instruction>(V)) {
       APInt Mask = DB->getDemandedBits(I);
       unsigned BitWidth2 = Mask.getBitWidth() - Mask.countl_zero();
-      while (!IsSigned && BitWidth2 < OrigBitWidth) {
-        APInt Mask = APInt::getBitsSetFrom(OrigBitWidth, BitWidth2 - 1);
-        if (MaskedValueIsZero(V, Mask, SimplifyQuery(*DL)))
-          break;
-        BitWidth2 *= 2;
-      }
       BitWidth1 = std::min(BitWidth1, BitWidth2);
     }
     BitWidth = std::max(BitWidth, BitWidth1);

diff  --git a/llvm/test/Transforms/SLPVectorizer/RISCV/unsigned-node-trunc-with-signed-users.ll b/llvm/test/Transforms/SLPVectorizer/RISCV/unsigned-node-trunc-with-signed-users.ll
index 4f855e20fac4db..3c02817f1ac190 100644
--- a/llvm/test/Transforms/SLPVectorizer/RISCV/unsigned-node-trunc-with-signed-users.ll
+++ b/llvm/test/Transforms/SLPVectorizer/RISCV/unsigned-node-trunc-with-signed-users.ll
@@ -8,20 +8,18 @@ define void @test(ptr %p, i16 %load794) {
 ; CHECK-NEXT:    [[GEP799:%.*]] = getelementptr inbounds i8, ptr [[P]], i64 16
 ; CHECK-NEXT:    [[TMP1:%.*]] = load <2 x i16>, ptr [[P]], align 2
 ; CHECK-NEXT:    [[TMP2:%.*]] = load <2 x i16>, ptr [[GEP799]], align 2
-; CHECK-NEXT:    [[TMP3:%.*]] = zext <2 x i16> [[TMP1]] to <2 x i32>
-; CHECK-NEXT:    [[TMP4:%.*]] = zext <2 x i16> [[TMP2]] to <2 x i32>
-; CHECK-NEXT:    [[TMP7:%.*]] = sub nsw <2 x i32> [[TMP4]], [[TMP3]]
-; CHECK-NEXT:    [[TMP8:%.*]] = add nsw <2 x i32> [[TMP7]], <i32 3329, i32 3329>
+; CHECK-NEXT:    [[TMP3:%.*]] = sub <2 x i16> [[TMP2]], [[TMP1]]
+; CHECK-NEXT:    [[TMP4:%.*]] = add <2 x i16> [[TMP3]], <i16 3329, i16 3329>
 ; CHECK-NEXT:    [[TMP5:%.*]] = insertelement <2 x i32> poison, i32 [[ZEXT795]], i32 0
 ; CHECK-NEXT:    [[TMP6:%.*]] = shufflevector <2 x i32> [[TMP5]], <2 x i32> poison, <2 x i32> zeroinitializer
-; CHECK-NEXT:    [[TMP12:%.*]] = mul <2 x i32> [[TMP8]], [[TMP6]]
-; CHECK-NEXT:    [[TMP9:%.*]] = zext <2 x i32> [[TMP12]] to <2 x i64>
+; CHECK-NEXT:    [[TMP7:%.*]] = trunc <2 x i32> [[TMP6]] to <2 x i16>
+; CHECK-NEXT:    [[TMP8:%.*]] = mul <2 x i16> [[TMP4]], [[TMP7]]
+; CHECK-NEXT:    [[TMP9:%.*]] = zext <2 x i16> [[TMP8]] to <2 x i64>
 ; CHECK-NEXT:    [[TMP10:%.*]] = mul nuw nsw <2 x i64> [[TMP9]], <i64 5039, i64 5039>
 ; CHECK-NEXT:    [[TMP11:%.*]] = lshr <2 x i64> [[TMP10]], <i64 24, i64 24>
-; CHECK-NEXT:    [[TMP13:%.*]] = trunc <2 x i64> [[TMP11]] to <2 x i32>
-; CHECK-NEXT:    [[TMP20:%.*]] = mul <2 x i32> [[TMP13]], <i32 62207, i32 62207>
-; CHECK-NEXT:    [[TMP21:%.*]] = add <2 x i32> [[TMP20]], [[TMP12]]
-; CHECK-NEXT:    [[TMP14:%.*]] = trunc <2 x i32> [[TMP21]] to <2 x i16>
+; CHECK-NEXT:    [[TMP12:%.*]] = trunc <2 x i64> [[TMP11]] to <2 x i16>
+; CHECK-NEXT:    [[TMP13:%.*]] = mul <2 x i16> [[TMP12]], <i16 -3329, i16 -3329>
+; CHECK-NEXT:    [[TMP14:%.*]] = add <2 x i16> [[TMP13]], [[TMP8]]
 ; CHECK-NEXT:    [[TMP15:%.*]] = add <2 x i16> [[TMP14]], <i16 -3329, i16 -3329>
 ; CHECK-NEXT:    [[TMP16:%.*]] = icmp slt <2 x i16> [[TMP15]], zeroinitializer
 ; CHECK-NEXT:    [[TMP17:%.*]] = select <2 x i1> [[TMP16]], <2 x i16> [[TMP14]], <2 x i16> zeroinitializer