Improve code for passing constant longs as arguments to function calls.
For example, on this instruction:
call void %test(long 1234)
Instead of this:
mov %EAX, 1234
mov %ECX, 0
mov DWORD PTR [%ESP], %EAX
mov DWORD PTR [%ESP + 4], %ECX
call test
We now emit this:
mov DWORD PTR [%ESP], 1234
mov DWORD PTR [%ESP + 4], 0
call test
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12686 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/InstSelectSimple.cpp b/lib/Target/X86/InstSelectSimple.cpp
index 1d4b7c9..264a137 100644
--- a/lib/Target/X86/InstSelectSimple.cpp
+++ b/lib/Target/X86/InstSelectSimple.cpp
@@ -1339,11 +1339,19 @@
}
break;
case cLong:
- ArgReg = Args[i].Val ? getReg(Args[i].Val) : Args[i].Reg;
- addRegOffset(BuildMI(BB, X86::MOV32mr, 5),
- X86::ESP, ArgOffset).addReg(ArgReg);
- addRegOffset(BuildMI(BB, X86::MOV32mr, 5),
- X86::ESP, ArgOffset+4).addReg(ArgReg+1);
+ if (Args[i].Val && isa<ConstantInt>(Args[i].Val)) {
+ uint64_t Val = cast<ConstantInt>(Args[i].Val)->getRawValue();
+ addRegOffset(BuildMI(BB, X86::MOV32mi, 5),
+ X86::ESP, ArgOffset).addImm(Val & ~0U);
+ addRegOffset(BuildMI(BB, X86::MOV32mi, 5),
+ X86::ESP, ArgOffset+4).addImm(Val >> 32ULL);
+ } else {
+ ArgReg = Args[i].Val ? getReg(Args[i].Val) : Args[i].Reg;
+ addRegOffset(BuildMI(BB, X86::MOV32mr, 5),
+ X86::ESP, ArgOffset).addReg(ArgReg);
+ addRegOffset(BuildMI(BB, X86::MOV32mr, 5),
+ X86::ESP, ArgOffset+4).addReg(ArgReg+1);
+ }
ArgOffset += 4; // 8 byte entry, not 4.
break;