[llvm] [GlobalISel] support lowering of G_SHUFFLEVECTOR with pointer args (PR #141959)

Stanley Gambarin via llvm-commits llvm-commits at lists.llvm.org
Fri May 30 08:53:14 PDT 2025


https://github.com/stanleygambarin updated https://github.com/llvm/llvm-project/pull/141959

>From 4d055df3e9e6d7c8218aff0bc72a0bf226ec80b5 Mon Sep 17 00:00:00 2001
From: "Gambarin, Stanley" <stanley.gambarin at intel.com>
Date: Thu, 29 May 2025 07:45:34 -0700
Subject: [PATCH 1/3] [GlobalISel] support lowering of G_SHUFFLEVECTOR with
 pointer args

---
 .../CodeGen/GlobalISel/LegalizerHelper.cpp    |  6 +++---
 .../AMDGPU/shufflevector-pointer-crash.mir    | 21 +++++++++++++++++++
 2 files changed, 24 insertions(+), 3 deletions(-)
 create mode 100644 llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir

diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 7b18a98d7f3ca..83ba71e4c9d49 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -8446,10 +8446,10 @@ LegalizerHelper::lowerShuffleVector(MachineInstr &MI) {
     }
   }
 
-  if (DstTy.isScalar())
-    MIRBuilder.buildCopy(DstReg, BuildVec[0]);
-  else
+  if (DstTy.isVector())
     MIRBuilder.buildBuildVector(DstReg, BuildVec);
+  else
+    MIRBuilder.buildCopy(DstReg, BuildVec[0]);
   MI.eraseFromParent();
   return Legalized;
 }
diff --git a/llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir b/llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir
new file mode 100644
index 0000000000000..03b870b923454
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir
@@ -0,0 +1,21 @@
+# RUN: llc -march=amdgcn -run-pass=legalizer -verify-machineinstrs %s -o - 
+
+--- |
+  define i32 @test(i64 %arg) {
+    ret i32 0
+  }
+...
+name:            test
+tracksRegLiveness: true
+body: |
+  bb.0:
+    %9:_(p0) = G_CONSTANT i64 0
+    %10:_(<2 x p0>) = G_BUILD_VECTOR %9:_(p0), %9:_(p0)
+    %8:_(<2 x p0>) = G_LOAD %9:_(p0) :: (load (<2 x p0>) from `ptr null`, align 64)
+    %11:_(p0) = G_SHUFFLE_VECTOR %8:_(<2 x p0>), %10:_, shufflemask(0)
+    %12:_(s32), %13:_(s32) = G_UNMERGE_VALUES %11:_(p0)
+    $vgpr0 = COPY %12:_(s32)
+    $vgpr1 = COPY %13:_(s32)
+    SI_RETURN implicit $vgpr0, implicit $vgpr1
+...
+

>From a7c31d78e2a3fde8b815762a466fd3dbf5014c35 Mon Sep 17 00:00:00 2001
From: "Gambarin, Stanley" <stanley.gambarin at intel.com>
Date: Thu, 29 May 2025 14:27:19 -0700
Subject: [PATCH 2/3] fix recommendations

---
 .../AMDGPU/shufflevector-pointer-crash.mir    | 21 ++++++++++---------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir b/llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir
index 03b870b923454..ae65ef5fbaf4a 100644
--- a/llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir
+++ b/llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir
@@ -1,21 +1,22 @@
-# RUN: llc -march=amdgcn -run-pass=legalizer -verify-machineinstrs %s -o - 
+# RUN: llc -march=amdgcn -run-pass=legalizer -verify-machineinstrs %s -o -
 
 --- |
-  define i32 @test(i64 %arg) {
-    ret i32 0
+  define i32 @test() {
+    unreachable
   }
 ...
+---
 name:            test
 tracksRegLiveness: true
 body: |
   bb.0:
-    %9:_(p0) = G_CONSTANT i64 0
-    %10:_(<2 x p0>) = G_BUILD_VECTOR %9:_(p0), %9:_(p0)
-    %8:_(<2 x p0>) = G_LOAD %9:_(p0) :: (load (<2 x p0>) from `ptr null`, align 64)
-    %11:_(p0) = G_SHUFFLE_VECTOR %8:_(<2 x p0>), %10:_, shufflemask(0)
-    %12:_(s32), %13:_(s32) = G_UNMERGE_VALUES %11:_(p0)
-    $vgpr0 = COPY %12:_(s32)
-    $vgpr1 = COPY %13:_(s32)
+    %0:_(p0) = G_CONSTANT i64 0
+    %1:_(<2 x p0>) = G_BUILD_VECTOR %0:_(p0), %0:_(p0)
+    %2:_(<2 x p0>) = G_LOAD %0:_(p0) :: (load (<2 x p0>))
+    %3:_(p0) = G_SHUFFLE_VECTOR %2:_(<2 x p0>), %1:_, shufflemask(0)
+    %4:_(s32), %5:_(s32) = G_UNMERGE_VALUES %3:_(p0)
+    $vgpr0 = COPY %4:_(s32)
+    $vgpr1 = COPY %5:_(s32)
     SI_RETURN implicit $vgpr0, implicit $vgpr1
 ...
 

>From fc4a1d3668e7d281ca917aa1d069837626d2c501 Mon Sep 17 00:00:00 2001
From: "Gambarin, Stanley" <stanley.gambarin at intel.com>
Date: Fri, 30 May 2025 08:53:02 -0700
Subject: [PATCH 3/3] update test

---
 .../shufflevector-pointer-crash.mir           | 36 +++++++++++++++++++
 .../AMDGPU/shufflevector-pointer-crash.mir    | 22 ------------
 2 files changed, 36 insertions(+), 22 deletions(-)
 create mode 100644 llvm/test/CodeGen/AMDGPU/GlobalISel/shufflevector-pointer-crash.mir
 delete mode 100644 llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir

diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/shufflevector-pointer-crash.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/shufflevector-pointer-crash.mir
new file mode 100644
index 0000000000000..ac903adba9a47
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/shufflevector-pointer-crash.mir
@@ -0,0 +1,36 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+# RUN: llc -march=amdgcn -run-pass=legalizer %s -o - | FileCheck %s
+
+---
+name:            test
+tracksRegLiveness: true
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: test
+    ; CHECK: [[C:%[0-9]+]]:_(p0) = G_CONSTANT i64 0
+    ; CHECK-NEXT: [[LOAD:%[0-9]+]]:_(s32) = G_LOAD [[C]](p0) :: (load (s32), align 16)
+    ; CHECK-NEXT: [[C1:%[0-9]+]]:_(p0) = G_CONSTANT i64 4
+    ; CHECK-NEXT: [[LOAD1:%[0-9]+]]:_(s32) = G_LOAD [[C1]](p0) :: (load (s32) from unknown-address + 4)
+    ; CHECK-NEXT: [[C2:%[0-9]+]]:_(p0) = G_CONSTANT i64 8
+    ; CHECK-NEXT: [[LOAD2:%[0-9]+]]:_(s32) = G_LOAD [[C2]](p0) :: (load (s32) from unknown-address + 8, align 8)
+    ; CHECK-NEXT: [[C3:%[0-9]+]]:_(p0) = G_CONSTANT i64 12
+    ; CHECK-NEXT: [[LOAD3:%[0-9]+]]:_(s32) = G_LOAD [[C3]](p0) :: (load (s32) from unknown-address + 12)
+    ; CHECK-NEXT: [[BUILD_VECTOR:%[0-9]+]]:_(<4 x s32>) = G_BUILD_VECTOR [[LOAD]](s32), [[LOAD1]](s32), [[LOAD2]](s32), [[LOAD3]](s32)
+    ; CHECK-NEXT: [[BITCAST:%[0-9]+]]:_(<2 x p0>) = G_BITCAST [[BUILD_VECTOR]](<4 x s32>)
+    ; CHECK-NEXT: [[UV:%[0-9]+]]:_(p0), [[UV1:%[0-9]+]]:_(p0) = G_UNMERGE_VALUES [[BITCAST]](<2 x p0>)
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(p0) = COPY [[UV]](p0)
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(p0) = COPY [[COPY]](p0)
+    ; CHECK-NEXT: [[UV2:%[0-9]+]]:_(s32), [[UV3:%[0-9]+]]:_(s32) = G_UNMERGE_VALUES [[COPY1]](p0)
+    ; CHECK-NEXT: $vgpr0 = COPY [[UV2]](s32)
+    ; CHECK-NEXT: $vgpr1 = COPY [[UV3]](s32)
+    ; CHECK-NEXT: SI_RETURN implicit $vgpr0, implicit $vgpr1
+    %0:_(p0) = G_CONSTANT i64 0
+    %1:_(<2 x p0>) = G_BUILD_VECTOR %0:_(p0), %0:_(p0)
+    %2:_(<2 x p0>) = G_LOAD %0:_(p0) :: (load (<2 x p0>))
+    %3:_(p0) = G_SHUFFLE_VECTOR %2:_(<2 x p0>), %1:_, shufflemask(0)
+    %4:_(s32), %5:_(s32) = G_UNMERGE_VALUES %3:_(p0)
+    $vgpr0 = COPY %4:_(s32)
+    $vgpr1 = COPY %5:_(s32)
+    SI_RETURN implicit $vgpr0, implicit $vgpr1
+...
+
diff --git a/llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir b/llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir
deleted file mode 100644
index ae65ef5fbaf4a..0000000000000
--- a/llvm/test/CodeGen/AMDGPU/shufflevector-pointer-crash.mir
+++ /dev/null
@@ -1,22 +0,0 @@
-# RUN: llc -march=amdgcn -run-pass=legalizer -verify-machineinstrs %s -o -
-
---- |
-  define i32 @test() {
-    unreachable
-  }
-...
----
-name:            test
-tracksRegLiveness: true
-body: |
-  bb.0:
-    %0:_(p0) = G_CONSTANT i64 0
-    %1:_(<2 x p0>) = G_BUILD_VECTOR %0:_(p0), %0:_(p0)
-    %2:_(<2 x p0>) = G_LOAD %0:_(p0) :: (load (<2 x p0>))
-    %3:_(p0) = G_SHUFFLE_VECTOR %2:_(<2 x p0>), %1:_, shufflemask(0)
-    %4:_(s32), %5:_(s32) = G_UNMERGE_VALUES %3:_(p0)
-    $vgpr0 = COPY %4:_(s32)
-    $vgpr1 = COPY %5:_(s32)
-    SI_RETURN implicit $vgpr0, implicit $vgpr1
-...
-



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