AMDGPU: enable 128-bit for local addr space under an option

Author: Samuel Pitoiset

ds_read_b128 and ds_write_b128 have been recently enabled
under the amdgpu-ds128 option because the performance benefit
is unclear.

Though, using 128-bit loads/stores for the local address space
appears to introduce regressions in tessellation shaders. Not
sure what is broken, but as ds_read_b128/ds_write_b128 are not
enabled by default, just introduce a global option and enable
128-bit only if requested (until it's fixed/used correctly).

v2: - fix regressions in merge-stores.ll and multiple_tails.ll

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105464
llvm-svn: 329764
This commit is contained in:
Marek Olsak 2018-04-10 22:48:23 +00:00
parent 3dc27f1a69
commit a9a58fa236
13 changed files with 35 additions and 28 deletions

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@ -426,6 +426,12 @@ def FeatureEnableSIScheduler : SubtargetFeature<"si-scheduler",
"Enable SI Machine Scheduler"
>;
def FeatureEnableDS128 : SubtargetFeature<"enable-ds128",
"EnableDS128",
"true",
"Use ds_{read|write}_b128"
>;
// Unless +-flat-for-global is specified, turn on FlatForGlobal for
// all OS-es on VI and newer hardware to avoid assertion failures due
// to missing ADDR64 variants of MUBUF instructions.

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@ -132,6 +132,7 @@ AMDGPUSubtarget::AMDGPUSubtarget(const Triple &TT, StringRef GPU, StringRef FS,
EnableLoadStoreOpt(false),
EnableUnsafeDSOffsetFolding(false),
EnableSIScheduler(false),
EnableDS128(false),
DumpCode(false),
FP64(false),

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@ -133,6 +133,7 @@ protected:
bool EnableLoadStoreOpt;
bool EnableUnsafeDSOffsetFolding;
bool EnableSIScheduler;
bool EnableDS128;
bool DumpCode;
// Subtarget statically properties set by tablegen
@ -412,8 +413,8 @@ public:
/// \returns If target supports ds_read/write_b128 and user enables generation
/// of ds_read/write_b128.
bool useDS128(bool UserEnable) const {
return CIInsts && UserEnable;
bool useDS128() const {
return CIInsts && EnableDS128;
}
/// \returns If MUBUF instructions always perform range checking, even for

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@ -265,11 +265,13 @@ unsigned AMDGPUTTIImpl::getLoadStoreVecRegBitWidth(unsigned AddrSpace) const {
return 512;
}
if (AddrSpace == AS.FLAT_ADDRESS ||
AddrSpace == AS.LOCAL_ADDRESS ||
AddrSpace == AS.REGION_ADDRESS)
if (AddrSpace == AS.FLAT_ADDRESS)
return 128;
if (AddrSpace == AS.LOCAL_ADDRESS ||
AddrSpace == AS.REGION_ADDRESS)
return ST->useDS128() ? 128 : 64;
if (AddrSpace == AS.PRIVATE_ADDRESS)
return 8 * ST->getMaxPrivateElementSize();

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@ -94,11 +94,6 @@ static cl::opt<bool> EnableVGPRIndexMode(
cl::desc("Use GPR indexing mode instead of movrel for vector indexing"),
cl::init(false));
static cl::opt<bool> EnableDS128(
"amdgpu-ds128",
cl::desc("Use DS_read/write_b128"),
cl::init(false));
static cl::opt<unsigned> AssumeFrameIndexHighZeroBits(
"amdgpu-frame-index-zero-bits",
cl::desc("High bits of frame index assumed to be zero"),
@ -5300,7 +5295,7 @@ SDValue SITargetLowering::LowerLOAD(SDValue Op, SelectionDAG &DAG) const {
}
} else if (AS == AMDGPUASI.LOCAL_ADDRESS) {
// Use ds_read_b128 if possible.
if (Subtarget->useDS128(EnableDS128) && Load->getAlignment() >= 16 &&
if (Subtarget->useDS128() && Load->getAlignment() >= 16 &&
MemVT.getStoreSize() == 16)
return SDValue();
@ -5703,7 +5698,7 @@ SDValue SITargetLowering::LowerSTORE(SDValue Op, SelectionDAG &DAG) const {
}
} else if (AS == AMDGPUASI.LOCAL_ADDRESS) {
// Use ds_write_b128 if possible.
if (Subtarget->useDS128(EnableDS128) && Store->getAlignment() >= 16 &&
if (Subtarget->useDS128() && Store->getAlignment() >= 16 &&
VT.getStoreSize() == 16)
return SDValue();

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@ -3,9 +3,9 @@
; RUN: llc -march=r600 -mcpu=redwood < %s | FileCheck -check-prefixes=EG,FUNC %s
; Testing for ds_read/write_128
; RUN: llc -march=amdgcn -mcpu=tahiti -amdgpu-ds128 < %s | FileCheck -check-prefixes=SI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=tonga -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=tahiti -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=SI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=tonga -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; FUNC-LABEL: {{^}}load_f32_local:
; SICIVI: s_mov_b32 m0

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@ -5,8 +5,8 @@
; RUN: llc -march=r600 -mcpu=redwood < %s | FileCheck -check-prefixes=EG,FUNC %s
; Testing for ds_read_b128
; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -verify-machineinstrs -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -verify-machineinstrs -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; FUNC-LABEL: {{^}}local_load_f64:
; SICIV: s_mov_b32 m0

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@ -4,8 +4,8 @@
; RUN: llc -march=r600 -mcpu=redwood -verify-machineinstrs < %s | FileCheck -check-prefix=EG -check-prefix=FUNC %s
; Testing for ds_read/write_b128
; RUN: llc -march=amdgcn -mcpu=tonga -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=tonga -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; FUNC-LABEL: {{^}}local_load_i16:
; GFX9-NOT: m0

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@ -4,9 +4,9 @@
; RUN: llc -march=r600 -mcpu=redwood < %s | FileCheck -check-prefix=EG -check-prefix=FUNC %s
; Testing for ds_read/write_128
; RUN: llc -march=amdgcn -mcpu=tahiti -amdgpu-ds128 < %s | FileCheck -check-prefixes=SI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=tonga -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=tahiti -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=SI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=tonga -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; FUNC-LABEL: {{^}}local_load_i32:
; GCN-NOT: s_wqm_b64

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@ -5,8 +5,8 @@
; RUN: llc -march=r600 -mcpu=redwood < %s | FileCheck -check-prefixes=EG,FUNC %s
; Testing for ds_read/write_b128
; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -verify-machineinstrs -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -verify-machineinstrs -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; FUNC-LABEL: {{^}}local_load_i64:
; SICIVI: s_mov_b32 m0

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@ -4,8 +4,8 @@
; RUN: llc -march=r600 -mtriple=r600---amdgiz -mcpu=redwood -verify-machineinstrs < %s | FileCheck -check-prefix=EG -check-prefix=FUNC %s
; Testing for ds_read/write_b128
; RUN: llc -march=amdgcn -mcpu=tonga -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -amdgpu-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=tonga -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; RUN: llc -march=amdgcn -mcpu=gfx900 -mattr=+enable-ds128 < %s | FileCheck -check-prefixes=CIVI,FUNC %s
; FUNC-LABEL: {{^}}local_load_i8:
; GCN-NOT: s_wqm_b64

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@ -504,7 +504,8 @@ define amdgpu_kernel void @merge_local_store_2_constants_i32_align_2(i32 addrspa
}
; CHECK-LABEL: @merge_local_store_4_constants_i32
; CHECK: store <4 x i32> <i32 1234, i32 123, i32 456, i32 333>, <4 x i32> addrspace(3)*
; CHECK: store <2 x i32> <i32 456, i32 333>, <2 x i32> addrspace(3)*
; CHECK: store <2 x i32> <i32 1234, i32 123>, <2 x i32> addrspace(3)*
define amdgpu_kernel void @merge_local_store_4_constants_i32(i32 addrspace(3)* %out) #0 {
%out.gep.1 = getelementptr i32, i32 addrspace(3)* %out, i32 1
%out.gep.2 = getelementptr i32, i32 addrspace(3)* %out, i32 2

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@ -29,10 +29,11 @@ define amdgpu_kernel void @no_crash(i32 %arg) {
; longest chain vectorized
; CHECK-LABEL: @interleave_get_longest
; CHECK: load <4 x i32>
; CHECK: load <2 x i32>
; CHECK: load i32
; CHECK: store <2 x i32> zeroinitializer
; CHECK: load i32
; CHECK: load <2 x i32>
; CHECK: load i32
; CHECK: load i32