Dan Gohman | 1b733ae | 2010-01-04 20:53:54 +0000 | [diff] [blame^] | 1 | ;; X's live range extends beyond the shift, so the register allocator |
| 2 | ;; cannot coalesce it with Y. Because of this, a copy needs to be |
| 3 | ;; emitted before the shift to save the register value before it is |
| 4 | ;; clobbered. However, this copy is not needed if the register |
| 5 | ;; allocator turns the shift into an LEA. This also occurs for ADD. |
| 6 | |
| 7 | ; Check that the shift gets turned into an LEA. |
| 8 | ; RUN: llc < %s -march=x86 -x86-asm-syntax=intel | \ |
| 9 | ; RUN: not grep {mov E.X, E.X} |
| 10 | |
| 11 | @G = external global i32 ; <i32*> [#uses=3] |
| 12 | |
| 13 | define i32 @test1(i32 %X, i32 %Y) { |
| 14 | %Z = add i32 %X, %Y ; <i32> [#uses=1] |
| 15 | volatile store i32 %Y, i32* @G |
| 16 | volatile store i32 %Z, i32* @G |
| 17 | ret i32 %X |
| 18 | } |
| 19 | |
| 20 | define i32 @test2(i32 %X) { |
| 21 | %Z = add i32 %X, 1 ; <i32> [#uses=1] |
| 22 | volatile store i32 %Z, i32* @G |
| 23 | ret i32 %X |
| 24 | } |