llvm/test/CodeGen/X86/overlap-add.ll
2006-05-01 05:56:51 +00:00

28 lines
819 B
LLVM

;; X's live range extends beyond the shift, so the register allocator
;; cannot coalesce it with Y. Because of this, a copy needs to be
;; emitted before the shift to save the register value before it is
;; clobbered. However, this copy is not needed if the register
;; allocator turns the shift into an LEA. This also occurs for ADD.
; Check that the shift gets turned into an LEA.
; RUN: llvm-as < %s | llc -march=x86 -x86-asm-syntax=intel | not grep 'mov E.X, E.X'
; FIXME: We need live variable information about flags to do this xform safely. :(
; XFAIL: *
%G = external global int
int %test1(int %X, int %Y) {
%Z = add int %X, %Y
volatile store int %Y, int* %G
volatile store int %Z, int* %G
ret int %X
}
int %test2(int %X) {
%Z = add int %X, 1 ;; inc
volatile store int %Z, int* %G
ret int %X
}