[llvm] 6fdc2ce - [SLP]Fix PR77916: transform the whole mask, not only the elements for

[Alexey Bataev via llvm-commits]

Author: Alexey Bataev
Date: 2024-01-12T07:07:43-08:00
New Revision: 6fdc2ce8c507d3acf4e4b65beb66cfed68045588

URL: https://github.com/llvm/llvm-project/commit/6fdc2ce8c507d3acf4e4b65beb66cfed68045588
DIFF: https://github.com/llvm/llvm-project/commit/6fdc2ce8c507d3acf4e4b65beb66cfed68045588.diff

LOG: [SLP]Fix PR77916: transform the whole mask, not only the elements for
the second vector.

Need to transform all elements in the long mask, if we decided to
produce shorter version, some elements may still have incorrect inifices
after transformation for the first vector in the permutation.

Added: 
    llvm/test/Transforms/SLPVectorizer/X86/shuffle-mask-resized.ll

Modified: 
    llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 66a3c257a76f8c..ba804c10127e2c 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -7379,6 +7379,8 @@ class BoUpSLP::ShuffleCostEstimator : public BaseShuffleAnalysis {
             continue;
           if (Idx >= static_cast<int>(CommonVF))
             Idx = E1Mask[Idx - CommonVF] + VF;
+          else
+            Idx = E1Mask[Idx];
         }
         CommonVF = VF;
       }

diff  --git a/llvm/test/Transforms/SLPVectorizer/X86/shuffle-mask-resized.ll b/llvm/test/Transforms/SLPVectorizer/X86/shuffle-mask-resized.ll
new file mode 100644
index 00000000000000..7d493dac015a9c
--- /dev/null
+++ b/llvm/test/Transforms/SLPVectorizer/X86/shuffle-mask-resized.ll
@@ -0,0 +1,45 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -passes=slp-vectorizer -S -mtriple=x86_64-unknown-linux -slp-threshold=-10 < %s | FileCheck %s
+
+define i32 @test() {
+; CHECK-LABEL: define i32 @test() {
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    br label [[BB1:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[TMP0:%.*]] = phi <2 x i32> [ [[TMP5:%.*]], [[BB3:%.*]] ], [ zeroinitializer, [[BB:%.*]] ]
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <2 x i32> [[TMP0]], <2 x i32> poison, <8 x i32> <i32 0, i32 0, i32 0, i32 0, i32 0, i32 0, i32 1, i32 1>
+; CHECK-NEXT:    br i1 false, label [[BB4:%.*]], label [[BB3]]
+; CHECK:       bb3:
+; CHECK-NEXT:    [[TMP2:%.*]] = shufflevector <2 x i32> [[TMP0]], <2 x i32> <i32 0, i32 poison>, <2 x i32> <i32 2, i32 1>
+; CHECK-NEXT:    [[TMP3:%.*]] = add <2 x i32> zeroinitializer, [[TMP2]]
+; CHECK-NEXT:    [[TMP4:%.*]] = or <2 x i32> zeroinitializer, [[TMP2]]
+; CHECK-NEXT:    [[TMP5]] = shufflevector <2 x i32> [[TMP3]], <2 x i32> [[TMP4]], <2 x i32> <i32 0, i32 3>
+; CHECK-NEXT:    br label [[BB1]]
+; CHECK:       bb4:
+; CHECK-NEXT:    [[TMP6:%.*]] = phi <8 x i32> [ [[TMP1]], [[BB1]] ]
+; CHECK-NEXT:    ret i32 0
+;
+bb:
+  br label %bb1
+
+bb1:
+  %phi = phi i32 [ %or, %bb3 ], [ 0, %bb ]
+  %phi2 = phi i32 [ %add, %bb3 ], [ 0, %bb ]
+  br i1 false, label %bb4, label %bb3
+
+bb3:
+  %or = or i32 0, %phi
+  %add = add i32 0, 0
+  br label %bb1
+
+bb4:
+  %phi5 = phi i32 [ %phi2, %bb1 ]
+  %phi6 = phi i32 [ %phi2, %bb1 ]
+  %phi7 = phi i32 [ %phi2, %bb1 ]
+  %phi8 = phi i32 [ %phi2, %bb1 ]
+  %phi9 = phi i32 [ %phi2, %bb1 ]
+  %phi10 = phi i32 [ %phi2, %bb1 ]
+  %phi11 = phi i32 [ %phi, %bb1 ]
+  %phi12 = phi i32 [ %phi, %bb1 ]
+  ret i32 0
+}