//===----------------------------------------------------------------------===//
#include "llvm/ConstantHandling.h"
+#include "llvm/Instruction.h"
#include <cmath>
AnnotationID ConstRules::AID(AnnotationManager::getID("opt::ConstRules",
&ConstRules::find));
+// ConstantFoldInstruction - Attempt to constant fold the specified instruction.
+// If successful, the constant result is returned, if not, null is returned.
+//
+Constant *ConstantFoldInstruction(Instruction *I) {
+ Constant *Op0 = 0;
+ Constant *Op1 = 0;
+
+ if (I->getNumOperands() != 0) { // Get first operand if it's a constant...
+ Op0 = dyn_cast<Constant>(I->getOperand(0));
+ if (Op0 == 0) return 0; // Not a constant?, can't fold
+
+ if (I->getNumOperands() != 1) { // Get second operand if it's a constant...
+ Op1 = dyn_cast<Constant>(I->getOperand(1));
+ if (Op1 == 0) return 0; // Not a constant?, can't fold
+ }
+ }
+
+ switch (I->getOpcode()) {
+ case Instruction::Cast:
+ return ConstRules::get(*Op0)->castTo(Op0, I->getType());
+ case Instruction::Not: return ~*Op0;
+ case Instruction::Add: return *Op0 + *Op1;
+ case Instruction::Sub: return *Op0 - *Op1;
+ case Instruction::Mul: return *Op0 * *Op1;
+ case Instruction::Div: return *Op0 / *Op1;
+ case Instruction::Rem: return *Op0 % *Op1;
+
+ case Instruction::SetEQ: return *Op0 == *Op1;
+ case Instruction::SetNE: return *Op0 != *Op1;
+ case Instruction::SetLE: return *Op0 <= *Op1;
+ case Instruction::SetGE: return *Op0 >= *Op1;
+ case Instruction::SetLT: return *Op0 < *Op1;
+ case Instruction::SetGT: return *Op0 > *Op1;
+ case Instruction::Shl: return *Op0 << *Op1;
+ case Instruction::Shr: return *Op0 >> *Op1;
+ default:
+ return 0;
+ }
+}
+
+Constant *ConstantFoldCastInstruction(const Constant *V, const Type *DestTy) {
+ return ConstRules::get(*V)->castTo(V, DestTy);
+}
+
+Constant *ConstantFoldUnaryInstruction(unsigned Opcode, const Constant *V) {
+ switch (Opcode) {
+ case Instruction::Not: return ~*V;
+ }
+ return 0;
+}
+
+Constant *ConstantFoldBinaryInstruction(unsigned Opcode, const Constant *V1,
+ const Constant *V2) {
+ switch (Opcode) {
+ case Instruction::Add: return *V1 + *V2;
+ case Instruction::Sub: return *V1 - *V2;
+ case Instruction::Mul: return *V1 * *V2;
+ case Instruction::Div: return *V1 / *V2;
+ case Instruction::Rem: return *V1 % *V2;
+
+ case Instruction::SetEQ: return *V1 == *V2;
+ case Instruction::SetNE: return *V1 != *V2;
+ case Instruction::SetLE: return *V1 <= *V2;
+ case Instruction::SetGE: return *V1 >= *V2;
+ case Instruction::SetLT: return *V1 < *V2;
+ case Instruction::SetGT: return *V1 > *V2;
+ }
+ return 0;
+}
+
+Constant *ConstantFoldShiftInstruction(unsigned Opcode, const Constant *V1,
+ const Constant *V2) {
+ switch (Opcode) {
+ case Instruction::Shl: return *V1 << *V2;
+ case Instruction::Shr: return *V1 >> *V2;
+ default: return 0;
+ }
+}
+
+
//===----------------------------------------------------------------------===//
// TemplateRules Class
//===----------------------------------------------------------------------===//