Bug 1546728 - Build of qemu-kvm fails on ppc64 due to internal compiler error
Summary: Build of qemu-kvm fails on ppc64 due to internal compiler error
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: gcc
Version: 7.5
Hardware: powerpc
OS: Linux
unspecified
high
Target Milestone: rc
: 7.6
Assignee: Marek Polacek
QA Contact: Michael Petlan
Vladimír Slávik
URL:
Whiteboard:
Depends On:
Blocks: 1505884 1507957 1513404 1528344
TreeView+ depends on / blocked
 
Reported: 2018-02-19 12:50 UTC by Miroslav Rezanina
Modified: 2018-10-30 07:28 UTC (History)
13 users (show)

Fixed In Version: gcc-4.8.5-30.el7
Doc Type: Bug Fix
Doc Text:
Previously, GCC could crash on the PowerPC 64-bit architecture when trying to convert a vector shift-by-scalar into a shift-by-vector, because it used the wrong machine mode for the shift amount. This bug has been fixed and the shift amount now has the correct mode, so the conversion works and the code compiles without crashing.
Clone Of:
Environment:
Last Closed: 2018-10-30 07:27:17 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)
preprocessed source causing error. (961.13 KB, text/x-csrc)
2018-02-20 04:13 UTC, Miroslav Rezanina 		no flags Details
tcg-runtime-gvec.i (800.07 KB, application/octet-stream)
2018-04-17 06:52 UTC, IBM Bug Proxy 		no flags Details
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Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2018:3016 0 None None None 2018-10-30 07:28:48 UTC

Description Miroslav Rezanina 2018-02-19 12:50:16 UTC 
Description of problem:

When building latest upstream QEMU on ppc64le architecture build fails with following error:


/root/weekly/qemu-kvm/accel/tcg/tcg-runtime-gvec.c: In function ‘helper_gvec_shl8i’:
/root/weekly/qemu-kvm/accel/tcg/tcg-runtime-gvec.c:558:26: internal compiler error: in emit_move_insn, at expr.c:3495
         *(vec8 *)(d + i) = (*(vec8 *)(a + i) << shift);

Preprocessed source attached.
Comment 2 Jeff Nelson 2018-02-19 23:10:50 UTC 
Can you provide the attachment?
Comment 3 Miroslav Rezanina 2018-02-20 04:13:51 UTC 
Created attachment 1398070 [details]
preprocessed source causing error.
Comment 4 Miroslav Rezanina 2018-02-20 04:14:46 UTC 
Sorry, not sure why wasn't attachment added (added in form for new bug).
Comment 5 Marek Polacek 2018-02-20 14:27:54 UTC 
I'll see if I can bisect it but I'm afraid it's too late for 7.5.
Comment 6 Marek Polacek 2018-02-20 16:26:27 UTC 
Fixed by http://gcc.gnu.org/r227444.   Seems backportable.
Comment 8 Laurent Vivier 2018-03-29 06:59:01 UTC 
Reproducer:

-- r.c -----8<--------------------------------------------------
typedef unsigned char U1 __attribute__((vector_size(16)));
typedef unsigned short U2 __attribute__((vector_size(16)));
typedef unsigned int U4 __attribute__((vector_size(16)));
typedef unsigned long long U8 __attribute__((vector_size(16)));
void helper(void *d, void *a, int shift, int i);
void helper(void *d, void *a, int shift, int i)
{
  *(U1 *)(d + i) = *(U1 *)(a + i) << shift;
  *(U2 *)(d + i) = *(U2 *)(a + i) << shift;
  *(U4 *)(d + i) = *(U4 *)(a + i) << shift;
  *(U8 *)(d + i) = *(U8 *)(a + i) << shift;
}
-- r.c -----8<--------------------------------------------------

$ cc -c -o r.o r.c
r.c: In function ‘helper’:
r.c:8:35: internal compiler error: in emit_move_insn, at expr.c:3495
   *(U1 *)(d + i) = *(U1 *)(a + i) << shift;
                                   ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://bugzilla.redhat.com/bugzilla> for instructions.
Preprocessed source stored into /tmp/ccpJ2XXm.out file, please attach this to your bugreport.
Comment 12 Matt Newsome 2018-04-16 20:47:26 UTC 
*** Bug 1565536 has been marked as a duplicate of this bug. ***
Comment 13 IBM Bug Proxy 2018-04-17 06:52:11 UTC 
Created attachment 1422920 [details]
tcg-runtime-gvec.i
Comment 15 Michael Petlan 2018-07-16 17:21:09 UTC 
Reproduced successfully with gcc-4.8.5-28.el7_5.1 on both ppc64 and ppc64le; works OK with gcc-4.8.5-36.el7.

VERIFIED
Comment 17 errata-xmlrpc 2018-10-30 07:27:17 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2018:3016
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