[llvm] [AArch64][GlobalISel] Use a integer type for extract narrowing. (PR #216254)

[David Green via llvm-commits]

https://github.com/davemgreen updated https://github.com/llvm/llvm-project/pull/216254

>From d5887a3a550a94b570fd2f7090f21ad2e7feced2 Mon Sep 17 00:00:00 2001
From: David Green <david.green at arm.com>
Date: Sat, 22 Aug 2026 07:14:19 +0100
Subject: [PATCH] [AArch64][GlobalISel] Use a integer type for extract
 narrowing.

---
 llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp           | 2 +-
 .../test/CodeGen/AArch64/GlobalISel/legalize-extracts.mir | 8 ++++----
 llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 6f85390fd4ede..0d7d19ce23762 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -7537,7 +7537,7 @@ LegalizerHelper::narrowScalarExtract(MachineInstr &MI, unsigned TypeIdx,
     Register SegReg = SrcRegs[i];
     if (ExtractOffset != 0 || SegSize != NarrowSize) {
       // A genuine extract is needed.
-      SegReg = MRI.createGenericVirtualRegister(LLT::scalar(SegSize));
+      SegReg = MRI.createGenericVirtualRegister(LLT::integer(SegSize));
       MIRBuilder.buildExtract(SegReg, SrcRegs[i], ExtractOffset);
     }
 
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-extracts.mir b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-extracts.mir
index 4c07318cd582d..2b15463685191 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-extracts.mir
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-extracts.mir
@@ -348,8 +348,8 @@ body: |
     ; CHECK-NEXT: {{  $}}
     ; CHECK-NEXT: %h0:_(i16) = COPY $h0
     ; CHECK-NEXT: [[MV:%[0-9]+]]:_(i64) = G_MERGE_VALUES %h0(i16), %h0(i16), %h0(i16), %h0(i16)
-    ; CHECK-NEXT: [[EXTRACT:%[0-9]+]]:_(s16) = G_EXTRACT [[MV]](i64), 1
-    ; CHECK-NEXT: %extract:_(i16) = COPY [[EXTRACT]](s16)
+    ; CHECK-NEXT: [[EXTRACT:%[0-9]+]]:_(i16) = G_EXTRACT [[MV]](i64), 1
+    ; CHECK-NEXT: %extract:_(i16) = COPY [[EXTRACT]](i16)
     ; CHECK-NEXT: $h0 = COPY %extract(i16)
     ; CHECK-NEXT: RET_ReallyLR implicit $h0
     %h0:_(i16) = COPY $h0
@@ -369,8 +369,8 @@ body: |
     ; CHECK-NEXT: {{  $}}
     ; CHECK-NEXT: %h0:_(i16) = COPY $h0
     ; CHECK-NEXT: [[MV:%[0-9]+]]:_(i64) = G_MERGE_VALUES %h0(i16), %h0(i16), %h0(i16), %h0(i16)
-    ; CHECK-NEXT: [[EXTRACT:%[0-9]+]]:_(s32) = G_EXTRACT [[MV]](i64), 1
-    ; CHECK-NEXT: %extract:_(i32) = COPY [[EXTRACT]](s32)
+    ; CHECK-NEXT: [[EXTRACT:%[0-9]+]]:_(i32) = G_EXTRACT [[MV]](i64), 1
+    ; CHECK-NEXT: %extract:_(i32) = COPY [[EXTRACT]](i32)
     ; CHECK-NEXT: $w0 = COPY %extract(i32)
     ; CHECK-NEXT: RET_ReallyLR implicit $w0
     %h0:_(i16) = COPY $h0
diff --git a/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp b/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
index 346f3d9a88390..7201a9a480355 100644
--- a/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
+++ b/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
@@ -3228,7 +3228,7 @@ TEST_F(AArch64GISelMITest, NarrowScalarExtract) {
   CHECK: [[UV:%[0-9]+]]:_(i32), [[UV1:%[0-9]+]]:_(i32) = G_UNMERGE_VALUES
   CHECK: [[COPY:%[0-9]+]]:_(i32) = COPY [[UV1]]
   CHECK: [[UV3:%[0-9]+]]:_(i32), [[UV4:%[0-9]+]]:_(i32) = G_UNMERGE_VALUES
-  CHECK: [[EXTR:%[0-9]+]]:_(s16) = G_EXTRACT [[UV3]]:_(i32), 0
+  CHECK: [[EXTR:%[0-9]+]]:_(i16) = G_EXTRACT [[UV3]]:_(i32), 0
   CHECK: [[COPY:%[0-9]+]]:_(i16) = COPY [[EXTR]]
   )";