| # NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py |
| # RUN: llc -mcpu=z13 -O3 -misched=ilpmin -systemz-subreg-liveness -verify-machineinstrs -start-before simple-register-coalescing %s -mtriple s390x-ibm-linux -stop-after machine-scheduler -o - | FileCheck %s |
| |
| # Check that when the register coalescer rematerializes a register to set |
| # only a sub register, it sets the subranges of the unused lanes as being dead |
| # at the definition point. |
| # |
| # The way that test exercises that comes in two steps: |
| # - First, we need the register coalescer to rematerialize something. |
| # In that test, %0 is rematerializable and will be rematerialized in |
| # %1 since %1 and %0 cannot be directly coalesced (they interfere). |
| # - Second, we indirectly check that the subranges are valid for %1 |
| # when, in the machine scheduler, we move the instructions that define %1 |
| # closer to the return instruction (i.e., we move MSFI and the rematerialized |
| # definition of %0 (i.e., %1 = LGHI 25) down). When doing that displacement, |
| # the scheduler updates the live-ranges of %1. When the subrange for the |
| # unused lane (here the subrange for %1.subreg_h32) was not correct, the |
| # scheduler would hit an assertion or access some invalid memory location |
| # making the compiler crash. |
| # |
| # Bottom line, this test checks what was intended if at the end, both %0 and %1 |
| # are defined with `LGHI 25` and the instructions defining %1 are right before |
| # the return instruction. |
| # |
| # PR41372 |
| --- |
| name: main |
| tracksRegLiveness: true |
| body: | |
| bb.0: |
| |
| ; CHECK-LABEL |
| ; CHECK-LABEL: name: main |
| ; CHECK: [[LGHI:%[0-9]+]]:gr64bit = LGHI 25 |
| ; CHECK: CHIMux [[LGHI]].subreg_l32, 0, implicit-def $cc |
| ; CHECK: [[LGHI1:%[0-9]+]]:gr64bit = LGHI 25 |
| ; CHECK: undef [[LGHI1]].subreg_l32:gr64bit = MSFI [[LGHI1]].subreg_l32, -117440512 |
| ; CHECK: Return implicit [[LGHI1]].subreg_l32 |
| %0:gr64bit = LGHI 25 |
| %1:gr32bit = COPY %0.subreg_l32 |
| %1:gr32bit = MSFI %1, -117440512 |
| %2:grx32bit = COPY %0.subreg_l32 |
| CHIMux killed %2, 0, implicit-def $cc |
| %3:gr32bit = COPY killed %1 |
| Return implicit %3 |
| ... |