[llvm] r309783 - AMDGPU: Fix clobbering CSR VGPRs when spilling SGPR to it
Matt Arsenault via llvm-commits
llvm-commits at lists.llvm.org
Tue Aug 1 18:52:45 PDT 2017
Author: arsenm
Date: Tue Aug 1 18:52:45 2017
New Revision: 309783
URL: http://llvm.org/viewvc/llvm-project?rev=309783&view=rev
Log:
AMDGPU: Fix clobbering CSR VGPRs when spilling SGPR to it
Modified:
llvm/trunk/lib/Target/AMDGPU/SIFrameLowering.cpp
llvm/trunk/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
llvm/trunk/lib/Target/AMDGPU/SIMachineFunctionInfo.h
llvm/trunk/test/CodeGen/AMDGPU/byval-frame-setup.ll
llvm/trunk/test/CodeGen/AMDGPU/call-graph-register-usage.ll
llvm/trunk/test/CodeGen/AMDGPU/callee-frame-setup.ll
llvm/trunk/test/CodeGen/AMDGPU/nested-calls.ll
Modified: llvm/trunk/lib/Target/AMDGPU/SIFrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/SIFrameLowering.cpp?rev=309783&r1=309782&r2=309783&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/SIFrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/AMDGPU/SIFrameLowering.cpp Tue Aug 1 18:52:45 2017
@@ -454,6 +454,15 @@ void SIFrameLowering::emitPrologue(Machi
.addImm(NumBytes * ST.getWavefrontSize())
.setMIFlag(MachineInstr::FrameSetup);
}
+
+ for (const SIMachineFunctionInfo::SGPRSpillVGPRCSR &Reg
+ : FuncInfo->getSGPRSpillVGPRs()) {
+ if (!Reg.FI.hasValue())
+ continue;
+ TII->storeRegToStackSlot(MBB, MBBI, Reg.VGPR, true,
+ Reg.FI.getValue(), &AMDGPU::VGPR_32RegClass,
+ &TII->getRegisterInfo());
+ }
}
void SIFrameLowering::emitEpilogue(MachineFunction &MF,
@@ -462,6 +471,19 @@ void SIFrameLowering::emitEpilogue(Machi
if (FuncInfo->isEntryFunction())
return;
+ const SISubtarget &ST = MF.getSubtarget<SISubtarget>();
+ const SIInstrInfo *TII = ST.getInstrInfo();
+ MachineBasicBlock::iterator MBBI = MBB.getFirstTerminator();
+
+ for (const SIMachineFunctionInfo::SGPRSpillVGPRCSR &Reg
+ : FuncInfo->getSGPRSpillVGPRs()) {
+ if (!Reg.FI.hasValue())
+ continue;
+ TII->loadRegFromStackSlot(MBB, MBBI, Reg.VGPR,
+ Reg.FI.getValue(), &AMDGPU::VGPR_32RegClass,
+ &TII->getRegisterInfo());
+ }
+
unsigned StackPtrReg = FuncInfo->getStackPtrOffsetReg();
if (StackPtrReg == AMDGPU::NoRegister)
return;
@@ -469,9 +491,6 @@ void SIFrameLowering::emitEpilogue(Machi
const MachineFrameInfo &MFI = MF.getFrameInfo();
uint32_t NumBytes = MFI.getStackSize();
- const SISubtarget &ST = MF.getSubtarget<SISubtarget>();
- const SIInstrInfo *TII = ST.getInstrInfo();
- MachineBasicBlock::iterator MBBI = MBB.getFirstTerminator();
DebugLoc DL;
// FIXME: Clarify distinction between no set SP and SP. For callee functions,
Modified: llvm/trunk/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp?rev=309783&r1=309782&r2=309783&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp (original)
+++ llvm/trunk/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp Tue Aug 1 18:52:45 2017
@@ -237,6 +237,15 @@ unsigned SIMachineFunctionInfo::addImpli
return ImplicitBufferPtrUserSGPR;
}
+static bool isCalleeSavedReg(const MCPhysReg *CSRegs, MCPhysReg Reg) {
+ for (unsigned I = 0; CSRegs[I]; ++I) {
+ if (CSRegs[I] == Reg)
+ return true;
+ }
+
+ return false;
+}
+
/// Reserve a slice of a VGPR to support spilling for FrameIndex \p FI.
bool SIMachineFunctionInfo::allocateSGPRSpillToVGPR(MachineFunction &MF,
int FI) {
@@ -258,6 +267,8 @@ bool SIMachineFunctionInfo::allocateSGPR
int NumLanes = Size / 4;
+ const MCPhysReg *CSRegs = TRI->getCalleeSavedRegs(&MF);
+
// Make sure to handle the case where a wide SGPR spill may span between two
// VGPRs.
for (int I = 0; I < NumLanes; ++I, ++NumVGPRSpillLanes) {
@@ -274,14 +285,21 @@ bool SIMachineFunctionInfo::allocateSGPR
return false;
}
- SpillVGPRs.push_back(LaneVGPR);
+ Optional<int> CSRSpillFI;
+ if (FrameInfo.hasCalls() && CSRegs && isCalleeSavedReg(CSRegs, LaneVGPR)) {
+ // TODO: Should this be a CreateSpillStackObject? This is technically a
+ // weird CSR spill.
+ CSRSpillFI = FrameInfo.CreateStackObject(4, 4, false);
+ }
+
+ SpillVGPRs.push_back(SGPRSpillVGPRCSR(LaneVGPR, CSRSpillFI));
// Add this register as live-in to all blocks to avoid machine verifer
// complaining about use of an undefined physical register.
for (MachineBasicBlock &BB : MF)
BB.addLiveIn(LaneVGPR);
} else {
- LaneVGPR = SpillVGPRs.back();
+ LaneVGPR = SpillVGPRs.back().VGPR;
}
SpillLanes.push_back(SpilledReg(LaneVGPR, VGPRIndex));
Modified: llvm/trunk/lib/Target/AMDGPU/SIMachineFunctionInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/SIMachineFunctionInfo.h?rev=309783&r1=309782&r2=309783&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/SIMachineFunctionInfo.h (original)
+++ llvm/trunk/lib/Target/AMDGPU/SIMachineFunctionInfo.h Tue Aug 1 18:52:45 2017
@@ -211,6 +211,19 @@ public:
bool hasReg() { return VGPR != AMDGPU::NoRegister;}
};
+ struct SGPRSpillVGPRCSR {
+ // VGPR used for SGPR spills
+ unsigned VGPR;
+
+ // If the VGPR is a CSR, the stack slot used to save/restore it in the
+ // prolog/epilog.
+ Optional<int> FI;
+
+ SGPRSpillVGPRCSR(unsigned V, Optional<int> F) :
+ VGPR(V),
+ FI(F) {}
+ };
+
private:
// SGPR->VGPR spilling support.
typedef std::pair<unsigned, unsigned> SpillRegMask;
@@ -219,7 +232,7 @@ private:
// frameindex key.
DenseMap<int, std::vector<SpilledReg>> SGPRToVGPRSpills;
unsigned NumVGPRSpillLanes = 0;
- SmallVector<unsigned, 2> SpillVGPRs;
+ SmallVector<SGPRSpillVGPRCSR, 2> SpillVGPRs;
public:
@@ -231,6 +244,10 @@ public:
ArrayRef<SpilledReg>() : makeArrayRef(I->second);
}
+ ArrayRef<SGPRSpillVGPRCSR> getSGPRSpillVGPRs() const {
+ return SpillVGPRs;
+ }
+
bool allocateSGPRSpillToVGPR(MachineFunction &MF, int FI);
void removeSGPRToVGPRFrameIndices(MachineFrameInfo &MFI);
Modified: llvm/trunk/test/CodeGen/AMDGPU/byval-frame-setup.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/byval-frame-setup.ll?rev=309783&r1=309782&r2=309783&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/byval-frame-setup.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/byval-frame-setup.ll Tue Aug 1 18:52:45 2017
@@ -30,10 +30,11 @@ entry:
; GCN-LABEL: {{^}}void_func_byval_struct_non_leaf:
; GCN: s_mov_b32 s5, s32
-; GCN: buffer_store_dword v32
+; GCN-DAG: buffer_store_dword v32
+; GCN-DAG: buffer_store_dword v33
; GCN: v_writelane_b32
-; GCN-DAG: s_add_u32 s32, s32, 0xa00{{$}}
+; GCN-DAG: s_add_u32 s32, s32, 0xb00{{$}}
; GCN-DAG: buffer_load_dword [[LOAD0:v[0-9]+]], off, s[0:3], s5 offset:4{{$}}
; GCN: v_add_i32_e32 [[ADD0:v[0-9]+]], vcc, 1, [[LOAD0]]
@@ -48,7 +49,8 @@ entry:
; GCN: v_readlane_b32
; GCN: buffer_load_dword v32,
-; GCN: s_sub_u32 s32, s32, 0xa00{{$}}
+; GCN: buffer_load_dword v33,
+; GCN: s_sub_u32 s32, s32, 0xb00{{$}}
; GCN: s_setpc_b64
define void @void_func_byval_struct_non_leaf(%struct.ByValStruct* byval noalias nocapture align 4 %arg0, %struct.ByValStruct* byval noalias nocapture align 4 %arg1) #1 {
entry:
@@ -67,7 +69,7 @@ entry:
; GCN-LABEL: {{^}}call_void_func_byval_struct_func:
; GCN: s_mov_b32 s5, s32
-; GCN: s_add_u32 s32, s32, 0xa00{{$}}
+; GCN: s_add_u32 s32, s32, 0xc00{{$}}
; GCN: v_writelane_b32
; GCN-DAG: s_add_u32 s32, s32, 0x800{{$}}
@@ -103,7 +105,7 @@ entry:
; GCN: v_readlane_b32
-; GCN: s_sub_u32 s32, s32, 0xa00{{$}}
+; GCN: s_sub_u32 s32, s32, 0xc00{{$}}
; GCN-NEXT: s_waitcnt
; GCN-NEXT: s_setpc_b64
define void @call_void_func_byval_struct_func() #0 {
Modified: llvm/trunk/test/CodeGen/AMDGPU/call-graph-register-usage.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/call-graph-register-usage.ll?rev=309783&r1=309782&r2=309783&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/call-graph-register-usage.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/call-graph-register-usage.ll Tue Aug 1 18:52:45 2017
@@ -146,7 +146,7 @@ define void @use_stack1() #1 {
}
; GCN-LABEL: {{^}}indirect_use_stack:
-; GCN: ScratchSize: 2120
+; GCN: ScratchSize: 2124
define void @indirect_use_stack() #1 {
%alloca = alloca [16 x i32], align 4
call void asm sideeffect "; use $0", "v"([16 x i32]* %alloca) #0
@@ -156,7 +156,7 @@ define void @indirect_use_stack() #1 {
; GCN-LABEL: {{^}}indirect_2_level_use_stack:
; GCN: is_dynamic_callstack = 0
-; GCN: ScratchSize: 2120
+; GCN: ScratchSize: 2124
define amdgpu_kernel void @indirect_2_level_use_stack() #0 {
call void @indirect_use_stack()
ret void
@@ -199,7 +199,7 @@ define amdgpu_kernel void @usage_externa
}
; GCN-LABEL: {{^}}direct_recursion_use_stack:
-; GCN: ScratchSize: 2052
+; GCN: ScratchSize: 2056
define void @direct_recursion_use_stack(i32 %val) #2 {
%alloca = alloca [512 x i32], align 4
call void asm sideeffect "; use $0", "v"([512 x i32]* %alloca) #0
@@ -218,7 +218,7 @@ ret:
; GCN-LABEL: {{^}}usage_direct_recursion:
; GCN: is_ptr64 = 1
; GCN: is_dynamic_callstack = 1
-; GCN: workitem_private_segment_byte_size = 2052
+; GCN: workitem_private_segment_byte_size = 2056
define amdgpu_kernel void @usage_direct_recursion(i32 %n) #0 {
call void @direct_recursion_use_stack(i32 %n)
ret void
Modified: llvm/trunk/test/CodeGen/AMDGPU/callee-frame-setup.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/callee-frame-setup.ll?rev=309783&r1=309782&r2=309783&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/callee-frame-setup.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/callee-frame-setup.ll Tue Aug 1 18:52:45 2017
@@ -36,14 +36,15 @@ define void @callee_with_stack() #0 {
; GCN-LABEL: {{^}}callee_with_stack_and_call:
; GCN: ; BB#0:
; GCN-NEXT: s_waitcnt
+; GCN: s_mov_b32 s5, s32
+; GCN: buffer_store_dword v32, off, s[0:3], s5 offset:8
-; GCN-DAG: s_mov_b32 s5, s32
; GCN-DAG: v_writelane_b32 v32, s33,
; GCN-DAG: v_writelane_b32 v32, s34,
; GCN-DAG: v_writelane_b32 v32, s35,
-; GCN-DAG: buffer_store_dword v0, off, s[0:3], s5 offset:4{{$}}
-; GCN-DAG: s_add_u32 s32, s32, 0x200{{$}}
+; GCN-DAG: s_add_u32 s32, s32, 0x300{{$}}
; GCN-DAG: v_mov_b32_e32 v0, 0{{$}}
+; GCN: buffer_store_dword v0, off, s[0:3], s5 offset:4{{$}}
; GCN-DAG: s_mov_b32 s33, s5
@@ -52,6 +53,7 @@ define void @callee_with_stack() #0 {
; GCN-DAG: v_readlane_b32 s35,
; GCN-DAG: v_readlane_b32 s34,
; GCN-DAG: v_readlane_b32 s33,
+; GCN: buffer_load_dword v32, off, s[0:3], s5 offset:8
; GCN: s_waitcnt
; GCN-NEXT: s_setpc_b64
define void @callee_with_stack_and_call() #0 {
@@ -64,13 +66,24 @@ define void @callee_with_stack_and_call(
; Should be able to copy incoming stack pointer directly to inner
; call's stack pointer argument.
+; There is stack usage only because of the need to evict a VGPR for
+; spilling CSR SGPRs.
+
; GCN-LABEL: {{^}}callee_no_stack_with_call:
; GCN: s_waitcnt
-; GCN-NOT: s32
+; GCN: s_mov_b32 s5, s32
+; GCN: buffer_store_dword v32, off, s[0:3], s5 offset:4
+; GCN-DAG: v_writelane_b32 v32, s33, 0
+; GCN-DAG: v_writelane_b32 v32, s34, 1
; GCN: s_mov_b32 s33, s5
; GCN: s_swappc_b64
; GCN: s_mov_b32 s5, s33
-; GCN-NOT: s32
+
+; GCN-DAG: v_readlane_b32 s34, v32, 1
+; GCN-DAG: v_readlane_b32 s33, v32, 0
+; GCN: buffer_load_dword v32, off, s[0:3], s5 offset:4
+; GCN: s_sub_u32 s32, s32, 0x200
+
; GCN: s_setpc_b64
define void @callee_no_stack_with_call() #0 {
call void @external_void_func_void()
Modified: llvm/trunk/test/CodeGen/AMDGPU/nested-calls.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/nested-calls.ll?rev=309783&r1=309782&r2=309783&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/nested-calls.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/nested-calls.ll Tue Aug 1 18:52:45 2017
@@ -9,9 +9,21 @@ declare void @external_void_func_i32(i32
; GCN-LABEL: {{^}}test_func_call_external_void_func_i32_imm:
; GCN: s_waitcnt
-; GCN-NOT: s32
+; GCN: s_mov_b32 s5, s32
+; Spill CSR VGPR used for SGPR spilling
+; GCN: buffer_store_dword v32, off, s[0:3], s5 offset:4
+; GCN-DAG: s_add_u32 s32, s32, 0x200
+; GCN-DAG: v_writelane_b32 v32, s33, 0
+; GCN-DAG: v_writelane_b32 v32, s34, 1
+; GCN-DAG: v_writelane_b32 v32, s35, 2
+
; GCN: s_swappc_b64
-; GCN-NOT: s32
+
+; GCN: v_readlane_b32 s35, v32, 2
+; GCN: v_readlane_b32 s34, v32, 1
+; GCN: v_readlane_b32 s33, v32, 0
+; GCN: buffer_load_dword v32, off, s[0:3], s5 offset:4
+; GCN: s_sub_u32 s32, s32, 0x200
; GCN: s_setpc_b64
define void @test_func_call_external_void_func_i32_imm() #0 {
call void @external_void_func_i32(i32 42)
@@ -21,10 +33,10 @@ define void @test_func_call_external_voi
; GCN-LABEL: {{^}}test_func_call_external_void_func_i32_imm_stack_use:
; GCN: s_waitcnt
; GCN: s_mov_b32 s5, s32
-; GCN: s_add_u32 s32, s32, 0x1100{{$}}
+; GCN: s_add_u32 s32, s32, 0x1200{{$}}
; GCN: buffer_store_dword v{{[0-9]+}}, off, s[0:3], s5 offset
; GCN: s_swappc_b64
-; GCN: s_sub_u32 s32, s32, 0x1100{{$}}
+; GCN: s_sub_u32 s32, s32, 0x1200{{$}}
; GCN: s_setpc_b64
define void @test_func_call_external_void_func_i32_imm_stack_use() #0 {
%alloca = alloca [16 x i32], align 4
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