[EVM] Handle target-cpu and target-features function attributes

Add support for handling target-features function attribute which
can be used to set EVM version. Currently, target-cpu is not
used, but maybe in a future it will be.

Signed-off-by: Vladimir Radosavljevic <vr@matterlabs.dev>

Author: vladimirradosavljevic

llvm/lib/Target/EVM/EVMTargetMachine.cpp

@@ -89,11 +89,29 @@ EVMTargetMachine::EVMTargetMachine(const Target &T, const Triple &TT,
     : CodeGenTargetMachineImpl(T, computeDataLayout(), TT, CPU, FS, Options,
                                getEffectiveRelocModel(RM),
                                getEffectiveCodeModel(CM, CodeModel::Small), OL),
-      TLOF(std::make_unique<EVMELFTargetObjectFile>()),
-      Subtarget(TT, std::string(CPU), std::string(FS), *this) {
+      TLOF(std::make_unique<EVMELFTargetObjectFile>()) {
   initAsmInfo();
 }
 
+const EVMSubtarget *
+EVMTargetMachine::getSubtargetImpl(const Function &F) const {
+  Attribute CPUAttr = F.getFnAttribute("target-cpu");
+  Attribute FSAttr = F.getFnAttribute("target-features");
+
+  auto CPU = CPUAttr.isValid() ? CPUAttr.getValueAsString().str() : TargetCPU;
+  auto FS = FSAttr.isValid() ? FSAttr.getValueAsString().str() : TargetFS;
+
+  auto &I = SubtargetMap[CPU + FS];
+  if (!I) {
+    // This needs to be done before we create a new subtarget since any
+    // creation will depend on the TM and the code generation flags on the
+    // function that reside in TargetOptions.
+    resetTargetOptions(F);
+    I = std::make_unique<EVMSubtarget>(TargetTriple, CPU, FS, *this);
+  }
+  return I.get();
+}
+
 TargetTransformInfo
 EVMTargetMachine::getTargetTransformInfo(const Function &F) const {
   return TargetTransformInfo(std::make_unique<EVMTTIImpl>(this, F));

llvm/lib/Target/EVM/EVMTargetMachine.h

@@ -22,7 +22,7 @@ namespace llvm {
 ///
 class EVMTargetMachine final : public CodeGenTargetMachineImpl {
   std::unique_ptr<TargetLoweringObjectFile> TLOF;
-  EVMSubtarget Subtarget;
+  mutable StringMap<std::unique_ptr<EVMSubtarget>> SubtargetMap;
 
 public:
   EVMTargetMachine(const Target &T, const Triple &TT, StringRef CPU,
@@ -33,9 +33,11 @@ class EVMTargetMachine final : public CodeGenTargetMachineImpl {
 
   TargetPassConfig *createPassConfig(PassManagerBase &PM) override;
 
-  const EVMSubtarget *getSubtargetImpl(const Function &F) const override {
-    return &Subtarget;
-  }
+  const EVMSubtarget *getSubtargetImpl(const Function &F) const override;
+  // DO NOT IMPLEMENT: There is no such thing as a valid default subtarget,
+  // subtargets are per-function entities based on the target-specific
+  // attributes of each function.
+  const EVMSubtarget *getSubtargetImpl() const = delete;
 
   TargetTransformInfo getTargetTransformInfo(const Function &F) const override;
 

llvm/test/CodeGen/EVM/clz-ctz.ll

@@ -130,19 +130,37 @@ define i256 @clz(i256 %v) {
   ret i256 %res
 }
 
+define i256 @clz_target_features(i256 %v) "target-features"="+osaka" {
+; GENERIC-LABEL: clz_target_features:
+; GENERIC:       ; %bb.0:
+; GENERIC-NEXT:    JUMPDEST
+; GENERIC-NEXT:    CLZ
+; GENERIC-NEXT:    SWAP1
+; GENERIC-NEXT:    JUMP
+;
+; OSAKA-LABEL: clz_target_features:
+; OSAKA:       ; %bb.0:
+; OSAKA-NEXT:    JUMPDEST
+; OSAKA-NEXT:    CLZ
+; OSAKA-NEXT:    SWAP1
+; OSAKA-NEXT:    JUMP
+  %res = call i256 @llvm.ctlz.i256(i256 %v, i1 false)
+  ret i256 %res
+}
+
 define i256 @ctz(i256 %v) {
 ; GENERIC-LABEL: ctz:
 ; GENERIC:       ; %bb.0:
 ; GENERIC-NEXT:    JUMPDEST
 ; GENERIC-NEXT:    DUP1
-; GENERIC-NEXT:    PUSH4 @.BB1_2
+; GENERIC-NEXT:    PUSH4 @.BB2_2
 ; GENERIC-NEXT:    JUMPI
 ; GENERIC-NEXT:  ; %bb.1:
 ; GENERIC-NEXT:    POP
 ; GENERIC-NEXT:    PUSH2 0x100
 ; GENERIC-NEXT:    SWAP1
 ; GENERIC-NEXT:    JUMP
-; GENERIC-NEXT:  .BB1_2: ; %cond.false
+; GENERIC-NEXT:  .BB2_2: ; %cond.false
 ; GENERIC-NEXT:    JUMPDEST
 ; GENERIC-NEXT:    PUSH32 0x101010101010101010101010101010101010101010101010101010101010101
 ; GENERIC-NEXT:    PUSH16 0xF0F0F0F0F0F0F0F0F0F0F0F0F0F0F0F