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https://github.com/c64scene-ar/llvm-6502.git
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ce6096f49b
to function calls, we would emit dead code, like this:
int Y(int, short, double);
int X() {
Y(4, 123, 4);
}
--- Old
X:
sub %ESP, 20
mov %EAX, 4
mov DWORD PTR [%ESP], %EAX
*** mov %AX, 123
mov %AX, 123
movsx %EAX, %AX
mov DWORD PTR [%ESP + 4], %EAX
fld QWORD PTR [.CPIX_0]
fstp QWORD PTR [%ESP + 8]
call Y
mov %EAX, 0
# IMPLICIT_USE %EAX %ESP
add %ESP, 20
ret
Now we emit:
X:
sub %ESP, 20
mov %EAX, 4
mov DWORD PTR [%ESP], %EAX
mov %AX, 123
movsx %EAX, %AX
mov DWORD PTR [%ESP + 4], %EAX
fld QWORD PTR [.CPIX_0]
fstp QWORD PTR [%ESP + 8]
call Y
mov %EAX, 0
# IMPLICIT_USE %EAX %ESP
add %ESP, 20
ret
Next up, eliminate the mov AX and movsx entirely!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12026 91177308-0d34-0410-b5e6-96231b3b80d8