}
}
+ // i1 can be simplified in many cases.
+ if (C1->getType() == Type::getInt1Ty(Context)) {
+ switch (Opcode) {
+ case Instruction::Add:
+ case Instruction::Sub:
+ return ConstantExpr::getXor(const_cast<Constant*>(C1),
+ const_cast<Constant*>(C2));
+ case Instruction::Mul:
+ return ConstantExpr::getAnd(const_cast<Constant*>(C1),
+ const_cast<Constant*>(C2));
+ case Instruction::Shl:
+ case Instruction::LShr:
+ case Instruction::AShr:
+ // We can assume that C2 == 0. If it were one the result would be
+ // undefined because the shift value is as large as the bitwidth.
+ return const_cast<Constant*>(C1);
+ case Instruction::SDiv:
+ case Instruction::UDiv:
+ // We can assume that C2 == 1. If it were zero the result would be
+ // undefined through division by zero.
+ return const_cast<Constant*>(C1);
+ case Instruction::URem:
+ case Instruction::SRem:
+ // We can assume that C2 == 1. If it were zero the result would be
+ // undefined through division by zero.
+ return ConstantInt::getFalse(Context);
+ default:
+ break;
+ }
+ }
+
// We don't know how to fold this.
return 0;
}
--- /dev/null
+; RUN: llvm-as < %s | llvm-dis | FileCheck %s
+
+@X = external global i8
+@Y = external global i8
+@Z = external global i8
+
+global i1 add (i1 icmp ult (i8* @X, i8* @Y), i1 icmp ult (i8* @X, i8* @Z))
+; CHECK: xor
+global i1 sub (i1 icmp ult (i8* @X, i8* @Y), i1 icmp ult (i8* @X, i8* @Z))
+; CHECK: xor
+global i1 mul (i1 icmp ult (i8* @X, i8* @Y), i1 icmp ult (i8* @X, i8* @Z))
+; CHECK: and
+
+global i1 sdiv (i1 icmp ult (i8* @X, i8* @Y), i1 icmp ult (i8* @X, i8* @Z))
+; CHECK-NOT: @Z
+; CHECK: i1 icmp ult (i8* @X, i8* @Y)
+global i1 udiv (i1 icmp ult (i8* @X, i8* @Y), i1 icmp ult (i8* @X, i8* @Z))
+; CHECK-NOT: @Z
+; CHECK: i1 icmp ult (i8* @X, i8* @Y)
+global i1 srem (i1 icmp ult (i8* @X, i8* @Y), i1 icmp ult (i8* @X, i8* @Z))
+; CHECK-NOT: icmp
+; CHECK: i1 false
+global i1 urem (i1 icmp ult (i8* @X, i8* @Y), i1 icmp ult (i8* @X, i8* @Z))
+; CHECK-NOT: icmp
+; CHECK: i1 false