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llvm-project/llvm/test/CodeGen/SystemZ/regalloc-fast-invalid-kill-...

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[RegAllocFast] Don't insert kill flags of super-register for partial kill When reusing a register for a new definition, the fast register allocator used to insert a kill flag at the previous last use of that register to inform later passes that this register is free between the redef and the last use. However, this may be wrong when subregisters are involved. Indeed, a partially redef would have trigger a kill of the full super register, potentially wrongly marking all the other subregisters as free. Given we don't track which lanes are still live, we cannot set the kill flag in such case. Note: This bug has been latent for about 7 years (r104056). llvmg.org/PR33677 llvm-svn: 307428
2017-07-08 03:25:45 +08:00
# RUN: llc -verify-machineinstrs -run-pass regallocfast -mtriple s390x-ibm-linux -o - %s | FileCheck %s
--- |
@g_167 = external global [5 x i64], align 8
define void @main() local_unnamed_addr {
ret void
}
...
# Make sure the usage of different subregisters on the same virtual register
# does not result in invalid kill flags.
# PR33677
---
name: main
alignment: 2
tracksRegLiveness: true
registers:
- { id: 0, class: gr128bit }
- { id: 1, class: gr64bit }
- { id: 2, class: addr64bit }
Followup on Proposal to move MIR physical register namespace to '$' sigil. Discussed here: http://lists.llvm.org/pipermail/llvm-dev/2018-January/120320.html In preparation for adding support for named vregs we are changing the sigil for physical registers in MIR to '$' from '%'. This will prevent name clashes of named physical register with named vregs. llvm-svn: 323922
2018-02-01 06:04:26 +08:00
# CHECK: $r0q = L128
# CHECK-NEXT: $r0l = COPY renamable $r1l
[RegAllocFast] Don't insert kill flags of super-register for partial kill When reusing a register for a new definition, the fast register allocator used to insert a kill flag at the previous last use of that register to inform later passes that this register is free between the redef and the last use. However, this may be wrong when subregisters are involved. Indeed, a partially redef would have trigger a kill of the full super register, potentially wrongly marking all the other subregisters as free. Given we don't track which lanes are still live, we cannot set the kill flag in such case. Note: This bug has been latent for about 7 years (r104056). llvmg.org/PR33677 llvm-svn: 307428
2017-07-08 03:25:45 +08:00
# Although R0L partially redefines R0Q, it must not mark R0Q as kill
# because R1D is still live through that instruction.
Followup on Proposal to move MIR physical register namespace to '$' sigil. Discussed here: http://lists.llvm.org/pipermail/llvm-dev/2018-January/120320.html In preparation for adding support for named vregs we are changing the sigil for physical registers in MIR to '$' from '%'. This will prevent name clashes of named physical register with named vregs. llvm-svn: 323922
2018-02-01 06:04:26 +08:00
# CHECK-NOT: implicit killed $r0q
# CHECK-NEXT: $r2d = COPY renamable $r1d
[RegAllocFast] Don't insert kill flags of super-register for partial kill When reusing a register for a new definition, the fast register allocator used to insert a kill flag at the previous last use of that register to inform later passes that this register is free between the redef and the last use. However, this may be wrong when subregisters are involved. Indeed, a partially redef would have trigger a kill of the full super register, potentially wrongly marking all the other subregisters as free. Given we don't track which lanes are still live, we cannot set the kill flag in such case. Note: This bug has been latent for about 7 years (r104056). llvmg.org/PR33677 llvm-svn: 307428
2017-07-08 03:25:45 +08:00
# CHECK-NEXT: LARL
body: |
bb.0:
%0.subreg_hl32 = COPY %0.subreg_l32
%1 = COPY %0.subreg_l64
%2 = LARL @g_167
Followup on Proposal to move MIR physical register namespace to '$' sigil. Discussed here: http://lists.llvm.org/pipermail/llvm-dev/2018-January/120320.html In preparation for adding support for named vregs we are changing the sigil for physical registers in MIR to '$' from '%'. This will prevent name clashes of named physical register with named vregs. llvm-svn: 323922
2018-02-01 06:04:26 +08:00
STC %1.subreg_l32, %2, 8, $noreg
[RegAllocFast] Don't insert kill flags of super-register for partial kill When reusing a register for a new definition, the fast register allocator used to insert a kill flag at the previous last use of that register to inform later passes that this register is free between the redef and the last use. However, this may be wrong when subregisters are involved. Indeed, a partially redef would have trigger a kill of the full super register, potentially wrongly marking all the other subregisters as free. Given we don't track which lanes are still live, we cannot set the kill flag in such case. Note: This bug has been latent for about 7 years (r104056). llvmg.org/PR33677 llvm-svn: 307428
2017-07-08 03:25:45 +08:00
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