[llvm] 939d3d0 - [GISel][Legalizer] Rework `changeElementCountTo` (NFC) (#158617)

[via llvm-commits]

Author: Denis.G
Date: 2025-10-16T10:18:58+09:00
New Revision: 939d3d03458ac1d284c65a3daf31c1a632dd0fbe

URL: https://github.com/llvm/llvm-project/commit/939d3d03458ac1d284c65a3daf31c1a632dd0fbe
DIFF: https://github.com/llvm/llvm-project/commit/939d3d03458ac1d284c65a3daf31c1a632dd0fbe.diff

LOG: [GISel][Legalizer] Rework `changeElementCountTo` (NFC) (#158617)

Mutation `changeElementCountTo` now uses `ElementCount`

Added: 
    

Modified: 
    llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h
    llvm/lib/CodeGen/GlobalISel/LegalizeMutations.cpp
    llvm/unittests/CodeGen/GlobalISel/LegalizerInfoTest.cpp

Removed: 
    


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diff  --git a/llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h b/llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h
index 985544430a5a3..51318c9c2736d 100644
--- a/llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/LegalizerInfo.h
@@ -383,7 +383,8 @@ LLVM_ABI LegalizeMutation changeElementCountTo(unsigned TypeIdx,
 
 /// Keep the same scalar or element type as \p TypeIdx, but take the number of
 /// elements from \p Ty.
-LLVM_ABI LegalizeMutation changeElementCountTo(unsigned TypeIdx, LLT Ty);
+LLVM_ABI LegalizeMutation changeElementCountTo(unsigned TypeIdx,
+                                               ElementCount EC);
 
 /// Change the scalar size or element size to have the same scalar size as type
 /// index \p FromIndex. Unlike changeElementTo, this discards pointer types and

diff  --git a/llvm/lib/CodeGen/GlobalISel/LegalizeMutations.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizeMutations.cpp
index 25c1db91b05d8..ded4df4edc14c 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizeMutations.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizeMutations.cpp
@@ -55,12 +55,10 @@ LegalizeMutation LegalizeMutations::changeElementCountTo(unsigned TypeIdx,
 }
 
 LegalizeMutation LegalizeMutations::changeElementCountTo(unsigned TypeIdx,
-                                                         LLT NewEltTy) {
+                                                         ElementCount EC) {
   return [=](const LegalityQuery &Query) {
     const LLT OldTy = Query.Types[TypeIdx];
-    ElementCount NewEltCount = NewEltTy.isVector() ? NewEltTy.getElementCount()
-                                                   : ElementCount::getFixed(1);
-    return std::make_pair(TypeIdx, OldTy.changeElementCount(NewEltCount));
+    return std::make_pair(TypeIdx, OldTy.changeElementCount(EC));
   };
 }
 

diff  --git a/llvm/unittests/CodeGen/GlobalISel/LegalizerInfoTest.cpp b/llvm/unittests/CodeGen/GlobalISel/LegalizerInfoTest.cpp
index 7340f56b52f49..04cd66c7acb2a 100644
--- a/llvm/unittests/CodeGen/GlobalISel/LegalizerInfoTest.cpp
+++ b/llvm/unittests/CodeGen/GlobalISel/LegalizerInfoTest.cpp
@@ -420,12 +420,14 @@ TEST(LegalizerInfoTest, RuleSets) {
 
     // Raw type form
     LI.getActionDefinitionsBuilder(G_ADD)
-      .fewerElementsIf(typeIs(0, v4s32), changeElementCountTo(0, v2s32))
-      .fewerElementsIf(typeIs(0, v8s32), changeElementCountTo(0, s32))
-      .fewerElementsIf(typeIs(0, LLT::scalable_vector(4, 16)),
-                       changeElementCountTo(0, LLT::scalable_vector(2, 16)))
-      .fewerElementsIf(typeIs(0, LLT::scalable_vector(8, 16)),
-                       changeElementCountTo(0, s16));
+        .fewerElementsIf(typeIs(0, v4s32),
+                         changeElementCountTo(0, ElementCount::getFixed(2)))
+        .fewerElementsIf(typeIs(0, v8s32),
+                         changeElementCountTo(0, ElementCount::getFixed(1)))
+        .fewerElementsIf(typeIs(0, LLT::scalable_vector(4, s16)),
+                         changeElementCountTo(0, ElementCount::getScalable(2)))
+        .fewerElementsIf(typeIs(0, LLT::scalable_vector(8, s16)),
+                         changeElementCountTo(0, ElementCount::getFixed(1)));
 
     LegacyInfo.computeTables();