# RUN: llc %s -mtriple=s390x-linux-gnu -mcpu=z13 \
# RUN: -start-before=register-coalescer -o - 2>&1 > /dev/null
# Test that the SystemZ shouldCoalesce() implementation does not crash in
# case of an undef use in another MBB. This was discovered in testing with
# -systemz-subreg-liveness.
--- |
@g_74 = external dso_local unnamed_addr global i32, align 4
@g_193 = external dso_local unnamed_addr global i32, align 4
define dso_local void @main() local_unnamed_addr {
%1 = load i32, ptr @g_193
%2 = or i32 %1, -1395153718
%3 = sdiv i32 -1395153718, %2
br i1 undef, label %5, label %4
; <label>:4: ; preds = %0
store i32 %3, ptr @g_74
store i32 -9, ptr @g_74
ret void
; <label>:5: ; preds = %0
unreachable
}
...
---
name: main
alignment: 16
tracksRegLiveness: true
registers:
- { id: 0, class: grx32bit }
- { id: 1, class: addr64bit }
- { id: 2, class: gr32bit }
- { id: 3, class: gr32bit }
- { id: 4, class: gr64bit }
- { id: 5, class: gr128bit }
- { id: 6, class: gr128bit }
- { id: 7, class: grx32bit }
- { id: 8, class: gr32bit }
- { id: 9, class: gr128bit }
body: |
bb.0 (%ir-block.0):
successors: %bb.2(0x00000001), %bb.1(0x7fffffff)
%1:addr64bit = LARL @g_193
%2:gr32bit = IIFMux 2899813578
%3:gr32bit = COPY killed %2
%3:gr32bit = O %3, killed %1, 0, $noreg, implicit-def dead $cc :: (dereferenceable load (s32) from @g_193)
%4:gr64bit = LGFI -1395153718
undef %5.subreg_l64:gr128bit = COPY killed %4
%6:gr128bit = COPY killed %5
dead %6:gr128bit = DSGFR %6, killed %3
%7:grx32bit = LHIMux 0
CHIMux killed %7, 0, implicit-def $cc
BRC 14, 6, %bb.2, implicit killed $cc
J %bb.1
bb.1 (%ir-block.4):
%8:gr32bit = LHIMux -9
STRL killed %8, @g_74 :: (store (s32) into @g_74)
Return
bb.2 (%ir-block.5):
dead %0:grx32bit = COPY undef %6.subreg_l32
...
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