[llvm] [AMDGPU] Require aligned VGPRs for gfx1250 (PR #145561)

Stanislav Mekhanoshin via llvm-commits llvm-commits at lists.llvm.org
Tue Jun 24 10:47:35 PDT 2025


https://github.com/rampitec created https://github.com/llvm/llvm-project/pull/145561

None

>From b62f0bafd562b96ce4d1ed300ca86686fed97b5c Mon Sep 17 00:00:00 2001
From: Stanislav Mekhanoshin <Stanislav.Mekhanoshin at amd.com>
Date: Tue, 24 Jun 2025 10:46:44 -0700
Subject: [PATCH] [AMDGPU] Require aligned VGPRs for gfx1250

---
 llvm/lib/Target/AMDGPU/GCNSubtarget.h         |   2 +-
 .../AMDGPU/alloc-aligned-tuples-gfx1250.mir   | 148 ++++++++++++++++++
 2 files changed, 149 insertions(+), 1 deletion(-)
 create mode 100644 llvm/test/CodeGen/AMDGPU/alloc-aligned-tuples-gfx1250.mir

diff --git a/llvm/lib/Target/AMDGPU/GCNSubtarget.h b/llvm/lib/Target/AMDGPU/GCNSubtarget.h
index d3c0eceddb34d..c8f194418ef50 100644
--- a/llvm/lib/Target/AMDGPU/GCNSubtarget.h
+++ b/llvm/lib/Target/AMDGPU/GCNSubtarget.h
@@ -1288,7 +1288,7 @@ class GCNSubtarget final : public AMDGPUGenSubtargetInfo,
   bool hasVALUReadSGPRHazard() const { return getGeneration() == GFX12; }
 
   /// Return if operations acting on VGPR tuples require even alignment.
-  bool needsAlignedVGPRs() const { return GFX90AInsts; }
+  bool needsAlignedVGPRs() const { return GFX90AInsts || GFX1250Insts; }
 
   /// Return true if the target has the S_PACK_HL_B32_B16 instruction.
   bool hasSPackHL() const { return GFX11Insts; }
diff --git a/llvm/test/CodeGen/AMDGPU/alloc-aligned-tuples-gfx1250.mir b/llvm/test/CodeGen/AMDGPU/alloc-aligned-tuples-gfx1250.mir
new file mode 100644
index 0000000000000..b88429d8a63f2
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/alloc-aligned-tuples-gfx1250.mir
@@ -0,0 +1,148 @@
+# RUN: llc -mtriple=amdgcn -mcpu=gfx1250 -start-before=greedy,0 -stop-after=virtregrewriter,2 -verify-machineinstrs -o - %s | FileCheck --check-prefixes=GCN,GFX1250 %s
+# Using the unaligned vector tuples are OK as long as they aren't used
+# in a real instruction.
+
+---
+# GCN-LABEL: name: alloc_vgpr_64
+# GFX1250: $vgpr4_vgpr5 = GLOBAL_LOAD
+name:            alloc_vgpr_64
+tracksRegLiveness: true
+liveins:
+  - { reg: '$vgpr0_vgpr1' }
+  - { reg: '$vgpr2' }
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1, $vgpr2
+
+    %0:vreg_64_align2 = COPY $vgpr0_vgpr1
+    %1:vgpr_32 = COPY $vgpr2
+    %2:vreg_64_align2 = GLOBAL_LOAD_DWORDX2 %0, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX2 %0, %2, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORD %0, %1, 0, 0, implicit $exec
+...
+
+---
+# GCN-LABEL: name: alloc_vgpr_96
+# GFX1250: $vgpr4_vgpr5_vgpr6 = GLOBAL_LOAD
+name:            alloc_vgpr_96
+tracksRegLiveness: true
+liveins:
+  - { reg: '$vgpr0_vgpr1' }
+  - { reg: '$vgpr2' }
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1, $vgpr2
+
+    %0:vreg_64_align2 = COPY $vgpr0_vgpr1
+    %1:vgpr_32 = COPY $vgpr2
+    %2:vreg_96_align2 = GLOBAL_LOAD_DWORDX3 %0, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX3 %0, %2, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORD %0, %1, 0, 0, implicit $exec
+...
+
+---
+# GCN-LABEL: name: alloc_vgpr_128
+# GFX1250: $vgpr4_vgpr5_vgpr6_vgpr7 = GLOBAL_LOAD
+name:            alloc_vgpr_128
+tracksRegLiveness: true
+liveins:
+  - { reg: '$vgpr0_vgpr1' }
+  - { reg: '$vgpr2' }
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1, $vgpr2
+
+    %0:vreg_64_align2 = COPY $vgpr0_vgpr1
+    %1:vgpr_32 = COPY $vgpr2
+    %2:vreg_128_align2 = GLOBAL_LOAD_DWORDX4 %0, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORD %0, %1, 0, 0, implicit $exec
+...
+
+---
+# GCN-LABEL: name: alloc_vgpr_160
+# GFX1250: $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8 = IMAGE_LOAD
+name:            alloc_vgpr_160
+tracksRegLiveness: true
+liveins:
+  - { reg: '$vgpr0_vgpr1' }
+  - { reg: '$vgpr2' }
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1, $vgpr2
+
+    %0:vreg_64_align2 = COPY $vgpr0_vgpr1
+    %1:vgpr_32 = COPY $vgpr2
+    %2:vreg_160_align2 = IMAGE_LOAD_V5_V1 %0.sub0, undef %3:sgpr_256, 0, 0, 0, 0, 0, 1, 0, 0, implicit $exec :: (dereferenceable load (s32), addrspace 4)
+    GLOBAL_STORE_DWORDX4 %0, %2.sub0_sub1_sub2_sub3, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORD %0, %1, 0, 0, implicit $exec
+...
+
+---
+# GCN-LABEL: name: alloc_vgpr_256
+# GFX1250: $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11 = COPY
+name:            alloc_vgpr_256
+tracksRegLiveness: true
+liveins:
+  - { reg: '$vgpr0_vgpr1' }
+  - { reg: '$vgpr2' }
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1, $vgpr2
+
+    %0:vreg_64_align2 = COPY $vgpr0_vgpr1
+    %1:vgpr_32 = COPY $vgpr2
+    %3:sgpr_256 = IMPLICIT_DEF
+    %2:vreg_256_align2 = COPY %3:sgpr_256
+    %4:vreg_128_align2 = IMAGE_SAMPLE_C_CL_O_V4_V8 %2, %3:sgpr_256, undef %5:sgpr_128, 0, 0, 0, 0, 0, 0, 0, 0, implicit $exec :: (dereferenceable load (s32), addrspace 4)
+    GLOBAL_STORE_DWORDX4 %0, %2.sub0_sub1_sub2_sub3, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORD %0, %1, 0, 0, implicit $exec
+...
+
+---
+# GCN-LABEL: name: alloc_vgpr_512
+# GFX1250: $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15_vgpr16_vgpr17_vgpr18_vgpr19 = IMPLICIT_DEF
+name:            alloc_vgpr_512
+tracksRegLiveness: true
+liveins:
+  - { reg: '$vgpr0_vgpr1' }
+  - { reg: '$vgpr2' }
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1, $vgpr2
+
+    %0:vreg_64_align2 = COPY $vgpr0_vgpr1
+    %1:vgpr_32 = COPY $vgpr2
+    %2:vreg_512_align2 = IMPLICIT_DEF
+    GLOBAL_STORE_DWORDX4 %0, %2.sub0_sub1_sub2_sub3, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2.sub4_sub5_sub6_sub7, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2.sub8_sub9_sub10_sub11, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2.sub12_sub13_sub14_sub15, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORD %0, %1, 0, 0, implicit $exec
+...
+
+---
+# GCN-LABEL: name: alloc_vgpr_1024
+# GFX1250: $vgpr4_vgpr5_vgpr6_vgpr7_vgpr8_vgpr9_vgpr10_vgpr11_vgpr12_vgpr13_vgpr14_vgpr15_vgpr16_vgpr17_vgpr18_vgpr19_vgpr20_vgpr21_vgpr22_vgpr23_vgpr24_vgpr25_vgpr26_vgpr27_vgpr28_vgpr29_vgpr30_vgpr31_vgpr32_vgpr33_vgpr34_vgpr35 = IMPLICIT_DEF
+name:            alloc_vgpr_1024
+tracksRegLiveness: true
+liveins:
+  - { reg: '$vgpr0_vgpr1' }
+  - { reg: '$vgpr2' }
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1, $vgpr2
+
+    %0:vreg_64_align2 = COPY $vgpr0_vgpr1
+    %1:vgpr_32 = COPY $vgpr2
+    %2:vreg_1024_align2 = IMPLICIT_DEF
+    GLOBAL_STORE_DWORDX4 %0, %2.sub0_sub1_sub2_sub3, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2.sub4_sub5_sub6_sub7, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2.sub8_sub9_sub10_sub11, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2.sub12_sub13_sub14_sub15, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2.sub16_sub17_sub18_sub19, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2.sub20_sub21_sub22_sub23, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2.sub24_sub25_sub26_sub27, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORDX4 %0, %2.sub28_sub29_sub30_sub31, 0, 0, implicit $exec
+    GLOBAL_STORE_DWORD %0, %1, 0, 0, implicit $exec
+...



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