[llvm] [SPIRV] Add FPVariant tracking for floating-point registers in SPIR-V (PR #156871)
via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 5 07:39:46 PDT 2025
https://github.com/YixingZhang007 updated https://github.com/llvm/llvm-project/pull/156871
>From b1ae15f6fac1675159d8acf003bb4b22f4e015e2 Mon Sep 17 00:00:00 2001
From: "Zhang, Yixing" <yixing.zhang at intel.com>
Date: Thu, 4 Sep 2025 05:14:39 -0700
Subject: [PATCH 1/4] add the support for bfloat in SPIRV
---
llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp | 26 ++++++++++++++++++-
llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.h | 13 ++++++++++
2 files changed, 38 insertions(+), 1 deletion(-)
diff --git a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
index cfe24c84941a9..0f258e03b23c8 100644
--- a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
@@ -1122,7 +1122,19 @@ SPIRVType *SPIRVGlobalRegistry::restOfCreateSPIRVType(
SPIRVType *SpirvType = createSPIRVType(Ty, MIRBuilder, AccessQual,
ExplicitLayoutRequired, EmitIR);
TypesInProcessing.erase(Ty);
- VRegToTypeMap[&MIRBuilder.getMF()][getSPIRVTypeID(SpirvType)] = SpirvType;
+
+ // Record the FPVariant of the floating-point registers in the
+ // VRegFPVariantMap.
+ MachineFunction *MF = &MIRBuilder.getMF();
+ Register TypeReg = getSPIRVTypeID(SpirvType);
+ if (Ty->isFloatingPointTy()) {
+ if (Ty->isBFloatTy()) {
+ VRegFPVariantMap[MF][TypeReg] = FPVariant::BRAIN_FLOAT;
+ } else {
+ VRegFPVariantMap[MF][TypeReg] = FPVariant::IEEE_FLOAT;
+ }
+ }
+ VRegToTypeMap[MF][TypeReg] = SpirvType;
// TODO: We could end up with two SPIR-V types pointing to the same llvm type.
// Is that a problem?
@@ -2088,3 +2100,15 @@ bool SPIRVGlobalRegistry::hasBlockDecoration(SPIRVType *Type) const {
}
return false;
}
+
+SPIRVGlobalRegistry::FPVariant
+SPIRVGlobalRegistry::getFPVariantForVReg(Register VReg,
+ const MachineFunction *MF) {
+ auto t = VRegFPVariantMap.find(MF ? MF : CurMF);
+ if (t != VRegFPVariantMap.end()) {
+ auto tt = t->second.find(VReg);
+ if (tt != t->second.end())
+ return tt->second;
+ }
+ return FPVariant::NONE;
+}
\ No newline at end of file
diff --git a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.h b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.h
index 7ef812828b7cc..1f8c30dc01f7f 100644
--- a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.h
+++ b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.h
@@ -29,6 +29,10 @@ using SPIRVType = const MachineInstr;
using StructOffsetDecorator = std::function<void(Register)>;
class SPIRVGlobalRegistry : public SPIRVIRMapping {
+public:
+ enum class FPVariant { NONE, IEEE_FLOAT, BRAIN_FLOAT };
+
+private:
// Registers holding values which have types associated with them.
// Initialized upon VReg definition in IRTranslator.
// Do not confuse this with DuplicatesTracker as DT maps Type* to <MF, Reg>
@@ -88,6 +92,11 @@ class SPIRVGlobalRegistry : public SPIRVIRMapping {
// map of aliasing decorations to aliasing metadata
std::unordered_map<const MDNode *, MachineInstr *> AliasInstMDMap;
+ // Maps floating point Registers to their FPVariant (float type kind), given
+ // the MachineFunction.
+ DenseMap<const MachineFunction *, DenseMap<Register, FPVariant>>
+ VRegFPVariantMap;
+
// Add a new OpTypeXXX instruction without checking for duplicates.
SPIRVType *createSPIRVType(const Type *Type, MachineIRBuilder &MIRBuilder,
SPIRV::AccessQualifier::AccessQualifier AQ,
@@ -422,6 +431,10 @@ class SPIRVGlobalRegistry : public SPIRVIRMapping {
// structures referring this instruction.
void invalidateMachineInstr(MachineInstr *MI);
+ // Return the FPVariant of to the given floating-point regiester.
+ FPVariant getFPVariantForVReg(Register VReg,
+ const MachineFunction *MF = nullptr);
+
private:
SPIRVType *getOpTypeBool(MachineIRBuilder &MIRBuilder);
>From 6fc5c9a741c1e4d885d022a4539cec6b0110c56b Mon Sep 17 00:00:00 2001
From: "Zhang, Yixing" <yixing.zhang at intel.com>
Date: Thu, 4 Sep 2025 05:56:56 -0700
Subject: [PATCH 2/4] nit
---
llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
index 0f258e03b23c8..e1bb2b912aa3c 100644
--- a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
@@ -2111,4 +2111,4 @@ SPIRVGlobalRegistry::getFPVariantForVReg(Register VReg,
return tt->second;
}
return FPVariant::NONE;
-}
\ No newline at end of file
+}
>From 1118490d6dfd7e264338949710174ea22dddac00 Mon Sep 17 00:00:00 2001
From: "Zhang, Yixing" <yixing.zhang at intel.com>
Date: Fri, 5 Sep 2025 07:31:11 -0700
Subject: [PATCH 3/4] nit change
---
llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
index e1bb2b912aa3c..6255ec5546ec7 100644
--- a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
@@ -2104,11 +2104,16 @@ bool SPIRVGlobalRegistry::hasBlockDecoration(SPIRVType *Type) const {
SPIRVGlobalRegistry::FPVariant
SPIRVGlobalRegistry::getFPVariantForVReg(Register VReg,
const MachineFunction *MF) {
- auto t = VRegFPVariantMap.find(MF ? MF : CurMF);
- if (t != VRegFPVariantMap.end()) {
- auto tt = t->second.find(VReg);
- if (tt != t->second.end())
- return tt->second;
+ const MachineFunction *Func = MF ? MF : CurMF;
+ DenseMap<const MachineFunction *, DenseMap<Register, FPVariant>>::const_iterator FuncIt =
+ VRegFPVariantMap.find(Func);
+
+ if (FuncIt != VRegFPVariantMap.end()) {
+ const DenseMap<Register, FPVariant> &VRegMap = FuncIt->second;
+ DenseMap<Register, FPVariant>::const_iterator VRegIt = VRegMap.find(VReg);
+
+ if (VRegIt != VRegMap.end())
+ return VRegIt->second;
}
return FPVariant::NONE;
}
>From f61cee2f2e7be311f59503f53e6185c362f52ce1 Mon Sep 17 00:00:00 2001
From: "Zhang, Yixing" <yixing.zhang at intel.com>
Date: Fri, 5 Sep 2025 07:39:32 -0700
Subject: [PATCH 4/4] solve clang format issue
---
llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
index 6255ec5546ec7..9ff5408f65d1a 100644
--- a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
@@ -2105,7 +2105,8 @@ SPIRVGlobalRegistry::FPVariant
SPIRVGlobalRegistry::getFPVariantForVReg(Register VReg,
const MachineFunction *MF) {
const MachineFunction *Func = MF ? MF : CurMF;
- DenseMap<const MachineFunction *, DenseMap<Register, FPVariant>>::const_iterator FuncIt =
+ DenseMap<const MachineFunction *,
+ DenseMap<Register, FPVariant>>::const_iterator FuncIt =
VRegFPVariantMap.find(Func);
if (FuncIt != VRegFPVariantMap.end()) {
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