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R600/SI: 64-bit and larger memory access must be at least 4-byte aligned

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This is true for SI only. CI+ supports unaligned memory accesses,
but this requires driver support, so for now we disallow unaligned
accesses for all GCN targets.

llvm-svn: 227822
This commit is contained in:
Tom Stellard 2015-02-02 18:02:28 +00:00
parent 79712c884f
commit 5e1403ebec
3 changed files with 80 additions and 9 deletions
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8
lib/Target/R600/SIISelLowering.cpp
View File

@ -315,9 +315,8 @@ bool SITargetLowering::allowsMisalignedMemoryAccesses(EVT VT,
if (!VT.isSimple() || VT == MVT::Other)
return false;
// XXX - CI changes say "Support for unaligned memory accesses" but I don't
// see what for specifically. The wording everywhere else seems to be the
// same.
// TODO - CI+ supports unaligned memory accesses, but this requires driver
// support.
// XXX - The only mention I see of this in the ISA manual is for LDS direct
// reads the "byte address and must be dword aligned". Is it also true for the
@ -334,7 +333,8 @@ bool SITargetLowering::allowsMisalignedMemoryAccesses(EVT VT,
// This applies to private, global, and constant memory.
if (IsFast)
*IsFast = true;
return VT.bitsGT(MVT::i32);
return VT.bitsGT(MVT::i32) && Align % 4 == 0;
}
EVT SITargetLowering::getOptimalMemOpType(uint64_t Size, unsigned DstAlign,

2
test/CodeGen/R600/cvt_f32_ubyte.ll
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@ -146,7 +146,7 @@ define void @load_v7i8_to_v7f32(<7 x float> addrspace(1)* noalias %out, <7 x i8>
; SI: buffer_store_dword
; SI: buffer_store_dword
define void @load_v8i8_to_v8f32(<8 x float> addrspace(1)* noalias %out, <8 x i8> addrspace(1)* noalias %in) nounwind {
%load = load <8 x i8> addrspace(1)* %in, align 1
%load = load <8 x i8> addrspace(1)* %in, align 8
%cvt = uitofp <8 x i8> %load to <8 x float>
store <8 x float> %cvt, <8 x float> addrspace(1)* %out, align 16
ret void

79
test/CodeGen/R600/unaligned-load-store.ll
View File

@ -1,18 +1,65 @@
; RUN: llc -march=amdgcn -mcpu=SI -verify-machineinstrs< %s | FileCheck -check-prefix=SI %s
; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs< %s | FileCheck -check-prefix=SI %s
; SI-LABEL: {{^}}unaligned_load_store_i32:
; SI-LABEL: {{^}}unaligned_load_store_i32_local:
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_write_b32
; SI: s_endpgm
define void @unaligned_load_store_i32(i32 addrspace(3)* %p, i32 addrspace(3)* %r) nounwind {
define void @unaligned_load_store_i32_local(i32 addrspace(3)* %p, i32 addrspace(3)* %r) nounwind {
%v = load i32 addrspace(3)* %p, align 1
store i32 %v, i32 addrspace(3)* %r, align 1
ret void
}
; SI-LABEL: {{^}}unaligned_load_store_v4i32:
; SI-LABEL: {{^}}unaligned_load_store_i32_global:
; SI: buffer_load_ubyte
; SI: buffer_load_ubyte
; SI: buffer_load_ubyte
; SI: buffer_load_ubyte
; SI: buffer_store_dword
define void @unaligned_load_store_i32_global(i32 addrspace(1)* %p, i32 addrspace(1)* %r) nounwind {
%v = load i32 addrspace(1)* %p, align 1
store i32 %v, i32 addrspace(1)* %r, align 1
ret void
}
; SI-LABEL: {{^}}unaligned_load_store_i64_local:
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_write2_b32
; SI: s_endpgm
define void @unaligned_load_store_i64_local(i64 addrspace(3)* %p, i64 addrspace(3)* %r) {
%v = load i64 addrspace(3)* %p, align 1
store i64 %v, i64 addrspace(3)* %r, align 1
ret void
}
; SI-LABEL: {{^}}unaligned_load_store_i64_global:
; SI: buffer_load_ubyte
; SI: buffer_load_ubyte
; SI: buffer_load_ubyte
; SI: buffer_load_ubyte
; SI: buffer_load_ubyte
; SI: buffer_load_ubyte
; SI: buffer_load_ubyte
; SI: buffer_load_ubyte
; SI: buffer_store_dwordx2
define void @unaligned_load_store_i64_global(i64 addrspace(1)* %p, i64 addrspace(1)* %r) {
%v = load i64 addrspace(1)* %p, align 1
store i64 %v, i64 addrspace(1)* %r, align 1
ret void
}
; SI-LABEL: {{^}}unaligned_load_store_v4i32_local:
; SI: ds_read_u8
; SI: ds_read_u8
; SI: ds_read_u8
@ -38,12 +85,36 @@ define void @unaligned_load_store_i32(i32 addrspace(3)* %p, i32 addrspace(3)* %r
; SI: ds_write_b32
; SI: ds_write_b32
; SI: s_endpgm
define void @unaligned_load_store_v4i32(<4 x i32> addrspace(3)* %p, <4 x i32> addrspace(3)* %r) nounwind {
define void @unaligned_load_store_v4i32_local(<4 x i32> addrspace(3)* %p, <4 x i32> addrspace(3)* %r) nounwind {
%v = load <4 x i32> addrspace(3)* %p, align 1
store <4 x i32> %v, <4 x i32> addrspace(3)* %r, align 1
ret void
}
; FIXME: We mark v4i32 as custom, so misaligned loads are never expanded.
; FIXME-SI-LABEL: {{^}}unaligned_load_store_v4i32_global
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
; FIXME-SI: buffer_load_ubyte
define void @unaligned_load_store_v4i32_global(<4 x i32> addrspace(1)* %p, <4 x i32> addrspace(1)* %r) nounwind {
%v = load <4 x i32> addrspace(1)* %p, align 1
store <4 x i32> %v, <4 x i32> addrspace(1)* %r, align 1
ret void
}
; SI-LABEL: {{^}}load_lds_i64_align_4:
; SI: ds_read2_b32
; SI: s_endpgm