[llvm-bugs] [Bug 35574] New: [Reg-alloc] Bad machine code: Live segment doesn't end at a valid instruction

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=35574

            Bug ID: 35574
           Summary: [Reg-alloc]  Bad machine code: Live segment doesn't
                    end at a valid instruction
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Register Allocator
          Assignee: unassignedbugs at nondot.org
          Reporter: paulsson at linux.vnet.ibm.com
                CC: llvm-bugs at lists.llvm.org

Created attachment 19529
  --> https://bugs.llvm.org/attachment.cgi?id=19529&action=edit
reduced testcase

Machine verifier complains after coalescing. Small reduced program attached.

bin/llc -mtriple=s390x-linux-gnu -mcpu=z13 tc_liveseg.ll -disable-machine-dce
-verify-machineinstrs

# After Simple Register Coalescing
********** INTERVALS **********
%0 [336r,336d:0)  0 at 336r
%1 [192r,240d:0)  0 at 192r
%3 [96r,128r:0)  0 at 96r
%5 [128r,192r:0)  0 at 128r
%13 [16r,32r:0)  0 at 16r
RegMasks:
********** MACHINEINSTRS **********
# Machine code for function main: NoPHIs, TracksLiveness

0B      %bb.0: derived from LLVM BB %0
16B             %13:grx32bit = LHIMux 0; GRX32Bit:%13
32B             CHIMux %13, 0, implicit-def %cc; GRX32Bit:%13
48B             BRC 14, 6, %bb.2, implicit killed %cc
64B             J %bb.1
            Successors according to CFG: %bb.1(0x00000001 / 0x80000000 = 0.00%)
%bb.2(0x7fffffff / 0x80000000 = 100.00%)

80B     %bb.1: derived from LLVM BB %3
            Predecessors according to CFG: %bb.0
96B             %3:addr64bit = LARL <ga:@g_979>; ADDR64Bit:%3
128B            %5:gr64bit = LG %3, 3, %noreg; mem:LD8[bitcast (i8*
getelementptr inbounds ({ i8, i8, i8, { i8, i8, i8, i8, i8, i8, i8, i8, i8, i8,
i8, i8, i8, i8, i8, i8, i8 } }, { i8, i8, i8, { i8, i8, i8, i8, i8, i8, i8, i8,
i8, i8, i8, i8, i8, i8, i8, i8, i8 } }* @g_979, i64 0, i32 3, i32 0) to
i136*)](align=1)(dereferenceable) GR64Bit:%5 ADDR64Bit:%3
192B            %1:gr64bit = SRLG %5, %noreg, 24; GR64Bit:%1,%5
336B            dead %0:gr64bit = LGHI 0; GR64Bit:%0

352B    %bb.2: derived from LLVM BB %4
            Predecessors according to CFG: %bb.0
368B            Return

# End machine code for function main.

*** Bad machine code: Live segment doesn't end at a valid instruction ***
- function:    main
- basic block: %bb.1  (0x2aa564e5ea8) [80B;352B)
- liverange:   [192r,240d:0)  0 at 192r
- v. register: %1
- segment:     [192r,240d:0)
LLVM ERROR: Found 1 machine code errors.

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20171208/68f4f799/attachment.html>