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[AMDGPU] Adjust VGPR allocation encoding on gfx1250 #156546

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Merged
merged 1 commit into from
Sep 2, 2025
Merged

[AMDGPU] Adjust VGPR allocation encoding on gfx1250 #156546

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3 changes: 3 additions & 0 deletions llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1376,6 +1376,9 @@ unsigned getVGPREncodingGranule(const MCSubtargetInfo *STI,
? *EnableWavefrontSize32
: STI->getFeatureBits().test(FeatureWavefrontSize32);

if (STI->getFeatureBits().test(Feature1024AddressableVGPRs))
return IsWave32 ? 16 : 8;

return IsWave32 ? 8 : 4;
}

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31 changes: 28 additions & 3 deletions llvm/test/MC/AMDGPU/hsa-gfx1250-v4.s
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Original file line number Diff line number Diff line change
@@ -1,11 +1,12 @@
// RUN: llvm-mc -triple amdgcn-amd-amdhsa -mcpu=gfx1250 --amdhsa-code-object-version=4 < %s | FileCheck --check-prefixes=ASM %s
// RUN: llvm-mc -triple amdgcn-amd-amdhsa -mcpu=gfx1250 --amdhsa-code-object-version=4 < %s | FileCheck --check-prefixes=ASM,W32 %s
// RUN: llvm-mc -triple amdgcn-amd-amdhsa -mcpu=gfx1250 --amdhsa-code-object-version=4 -filetype=obj < %s > %t
// RUN: llvm-readelf -S -r -s %t | FileCheck --check-prefix=READOBJ %s
// RUN: llvm-objdump -s -j .rodata %t | FileCheck --check-prefix=OBJDUMP %s
// RUN: not llvm-mc -triple amdgcn-amd-amdhsa -mcpu=gfx1250 -mattr=+wavefrontsize64,-wavefrontsize32 --amdhsa-code-object-version=4 < %s 2>&1 | FileCheck --check-prefix=W64-ERR %s

// READOBJ: Section Headers
// READOBJ: .text PROGBITS {{[0-9a-f]+}} {{[0-9a-f]+}} {{[0-9a-f]+}} {{[0-9]+}} AX {{[0-9]+}} {{[0-9]+}} 256
// READOBJ: .rodata PROGBITS {{[0-9a-f]+}} 000540 {{[0-9a-f]+}} {{[0-9]+}} A {{[0-9]+}} {{[0-9]+}} 64
// READOBJ: .rodata PROGBITS {{[0-9a-f]+}} 000640 {{[0-9a-f]+}} {{[0-9]+}} A {{[0-9]+}} {{[0-9]+}} 64

// READOBJ: Relocation section '.rela.rodata' at offset
// READOBJ: 0000000000000010 {{[0-9a-f]+}}00000005 R_AMDGPU_REL64 0000000000000000 .text + 10
Expand All @@ -20,11 +21,13 @@
// READOBJ-NEXT: 0000000000000200 0 FUNC LOCAL PROTECTED 2 special_sgpr
// READOBJ-NEXT: 0000000000000300 0 FUNC LOCAL PROTECTED 2 disabled_user_sgpr
// READOBJ-NEXT: 0000000000000400 0 FUNC LOCAL PROTECTED 2 max_lds_size
// READOBJ-NEXT: 0000000000000500 0 FUNC LOCAL PROTECTED 2 max_vgprs
// READOBJ-NEXT: 0000000000000000 64 OBJECT LOCAL DEFAULT 3 minimal.kd
// READOBJ-NEXT: 0000000000000040 64 OBJECT LOCAL DEFAULT 3 complete.kd
// READOBJ-NEXT: 0000000000000080 64 OBJECT LOCAL DEFAULT 3 special_sgpr.kd
// READOBJ-NEXT: 00000000000000c0 64 OBJECT LOCAL DEFAULT 3 disabled_user_sgpr.kd
// READOBJ-NEXT: 0000000000000100 64 OBJECT LOCAL DEFAULT 3 max_lds_size.kd
// READOBJ-NEXT: 0000000000000140 64 OBJECT LOCAL DEFAULT 3 max_vgprs.kd

// OBJDUMP: Contents of section .rodata
// Note, relocation for KERNEL_CODE_ENTRY_BYTE_OFFSET is not resolved here.
Expand All @@ -37,7 +40,7 @@
// OBJDUMP-NEXT: 0040 01000000 01000000 0c000000 00000000
// OBJDUMP-NEXT: 0050 00000000 00000000 00000000 00000000
// OBJDUMP-NEXT: 0060 00000000 00000000 00000000 00c00000
// OBJDUMP-NEXT: 0070 015021c4 410f007f 5e068200 00000000
// OBJDUMP-NEXT: 0070 005021c4 410f007f 5e068200 00000000
// special_sgpr
// OBJDUMP-NEXT: 0080 00000000 00000000 00000000 00000000
// OBJDUMP-NEXT: 0090 00000000 00000000 00000000 00000000
Expand All @@ -53,6 +56,11 @@
// OBJDUMP-NEXT: 0110 00000000 00000000 00000000 00000000
// OBJDUMP-NEXT: 0120 00000000 00000000 00000000 00000000
// OBJDUMP-NEXT: 0130 00000cc0 80000000 00040000 00000000
// max_vgprs
// OBJDUMP-NEXT: 0140 00000000 00000000 00000000 00000000
// OBJDUMP-NEXT: 0150 00000000 00000000 00000000 00000000
// OBJDUMP-NEXT: 0160 00000000 00000000 00000000 00000000
// OBJDUMP-NEXT: 0170 3f000cc0 80000000 00040000 00000000

.text

Expand Down Expand Up @@ -84,6 +92,11 @@ disabled_user_sgpr:
max_lds_size:
s_endpgm

.p2align 8
.type max_vgprs,@function
max_vgprs:
s_endpgm

.rodata
// ASM: .rodata

Expand Down Expand Up @@ -228,6 +241,18 @@ max_lds_size:
// ASM: .amdhsa_group_segment_fixed_size 393216
// ASM: .end_amdhsa_kernel

// Test maximum VGPR allocation

// ASM: .amdhsa_kernel max_vgprs
// W32: .amdhsa_next_free_vgpr 1024
// W64-ERR: error: value out of range
// ASM: .end_amdhsa_kernel
.p2align 6
.amdhsa_kernel max_vgprs
.amdhsa_next_free_vgpr 1024
.amdhsa_next_free_sgpr 1
.end_amdhsa_kernel

.section .foo

.byte .amdgcn.gfx_generation_number
Expand Down
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