YouCompleteMe/cpp/llvm/test/CodeGen/X86/overlap-shift.ll
2012-07-05 17:51:06 -07:00

20 lines
682 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: llc < %s -march=x86 -x86-asm-syntax=intel | \
; RUN: not grep {mov E.X, E.X}
@G = external global i32 ; <i32*> [#uses=1]
define i32 @test1(i32 %X) {
%Z = shl i32 %X, 2 ; <i32> [#uses=1]
store volatile i32 %Z, i32* @G
ret i32 %X
}