| # RUN: llc -mtriple=x86_64-- -run-pass=simple-register-coalescing -run-pass=regallocbasic -run-pass=virtregrewriter -late-remat-update-threshold=0 %s -o - | FileCheck %s |
| # |
| # PR40061: %t2 = %t1 is rematerialized and %t1 is added into toBeUpdated set |
| # to postpone its live interval update. After the rematerialization, the live |
| # interval of %t1 is larger than necessary. Then %t1 is merged into %t3 and %t1 |
| # gets removed. After the merge, %t3 contains live interval larger than |
| # necessary. Because %t3 is not in toBeUpdated set so its live interval is not |
| # updated after register coalescing, and it will break some assumption in |
| # regalloc. This test wants to check the live interval is up-to-date after |
| # register coalescing. |
| # |
| # To prevent the test from taking effect only in assert enabled mode, we want |
| # to achieve the test goal without dumping regalloc trace. We add strong hint |
| # to allocate both %t1 and %t2 to $rax register. If the %t1's live interval is |
| # not shrinked properly after register coalescing, %t1 and %t2 will not be |
| # both allocated to $rax because of inference, and we utilize the fact to |
| # achieve the test goal. But note that the assumption only holds when we use |
| # regallocbasic instead of greedy because greedy can update the live interval |
| # in the process of splitting. |
| # |
| # CHECK-LABEL: name: foo |
| # CHECK: bb.0.entry: |
| # CHECK: $rax = MOV64ri32 -11 |
| # CHECK: bb.1: |
| # CHECK: $rax = MOV64ri32 -11 |
| # CHECK: $rax = ADD64ri8 killed renamable $rax, 5 |
| # CHECK: CMP64ri8 renamable $rax |
| # CHECK: RET 0, $rax |
| # CHECK: bb.2: |
| # CHECK: $rax = ADD64ri8 killed renamable $rax, 10 |
| # CHECK: bb.3: |
| # CHECK: RET 0, $rax |
| --- |
| name: foo |
| body: | |
| bb.0.entry: |
| successors: %bb.1(0x15555555), %bb.2(0x6aaaaaab) |
| |
| %t1:gr64 = MOV64ri32 -11 |
| CMP64ri8 %t1, 1, implicit-def $eflags |
| JCC_1 %bb.2, 4, implicit killed $eflags |
| JMP_1 %bb.1 |
| |
| bb.1: |
| successors: %bb.1(0x80000000) |
| |
| %t2:gr64 = COPY %t1 |
| %t2:gr64 = ADD64ri8 %t2, 5, implicit-def $eflags |
| $rax = COPY %t2 |
| CMP64ri8 %t2, 1, implicit-def $eflags |
| JCC_1 %bb.1, 4, implicit killed $eflags |
| RET 0, $rax |
| |
| bb.2: |
| successors: %bb.3(0x80000000) |
| %t3:gr64 = COPY %t1 |
| %t3:gr64 = ADD64ri8 %t3, 10, implicit-def $eflags |
| |
| bb.3: |
| $rax = COPY %t3 |
| RET 0, $rax |
| |
| ... |