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From: "tuliom at ascii dot art.br" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/101324] New: powerpc64le: hashst appears before mflr at -O1 or higher
Date: Mon, 05 Jul 2021 15:32:31 +0000 [thread overview]
Message-ID: <bug-101324-4@http.gcc.gnu.org/bugzilla/> (raw)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101324
Bug ID: 101324
Summary: powerpc64le: hashst appears before mflr at -O1 or
higher
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: tuliom at ascii dot art.br
Target Milestone: ---
Created attachment 51105
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51105&action=edit
__memmove_ppc extracted from glibc
When using ROP (-mrop-protect), it's expected that generated code reads the
value from LR (mflr) and hash it later (hashst).
This works well at -O0.
However, at -O1 and higher, we're seeing cases where hashst appears before
mflr.
I'm attaching an example extracted from glibc.
You can reproduce the issue with command:
gcc -S -O1 -mrop-protect -mcpu=power10 memmove-ppc64.i -o -
The generated asm contains the following:
__memmove_ppc:
.LFB6:
.cfi_startproc
.localentry __memmove_ppc,1
hashst 0,-40(1)
std 28,-32(1)
stdu 1,-80(1)
.cfi_def_cfa_offset 80
.cfi_offset 28, -32
mr 28,3
subf 9,4,3
cmpld 0,9,5
bge 0,.L17
std 31,72(1)
.cfi_offset 31, -8
add 4,4,5
add 31,3,5
cmpldi 0,5,15
ble 0,.L4
mflr 0
...
next reply other threads:[~2021-07-05 15:32 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-05 15:32 tuliom at ascii dot art.br [this message]
2021-07-05 22:18 ` [Bug target/101324] " segher at gcc dot gnu.org
2021-07-05 23:54 ` segher at gcc dot gnu.org
2021-07-06 13:28 ` segher at gcc dot gnu.org
2021-07-06 13:46 ` tuliom at ascii dot art.br
2021-07-12 3:41 ` marxin at gcc dot gnu.org
2021-08-12 16:17 ` marxin at gcc dot gnu.org
2021-08-16 11:37 ` marxin at gcc dot gnu.org
2021-10-25 16:54 ` marxin at gcc dot gnu.org
2021-10-25 20:48 ` bergner at gcc dot gnu.org
2021-10-25 20:49 ` bergner at gcc dot gnu.org
2021-10-26 6:02 ` marxin at gcc dot gnu.org
2021-10-26 6:26 ` marxin at gcc dot gnu.org
2021-10-26 11:35 ` bergner at gcc dot gnu.org
2021-10-26 11:42 ` bergner at gcc dot gnu.org
2021-10-26 14:43 ` marxin at gcc dot gnu.org
2021-10-26 15:32 ` bergner at gcc dot gnu.org
2021-10-26 16:55 ` segher at gcc dot gnu.org
2021-10-26 19:08 ` bergner at gcc dot gnu.org
2021-10-27 20:08 ` bergner at gcc dot gnu.org
2021-10-27 20:09 ` bergner at gcc dot gnu.org
2021-10-28 3:19 ` bergner at gcc dot gnu.org
2021-12-03 20:32 ` cvs-commit at gcc dot gnu.org
2021-12-03 20:43 ` bergner at gcc dot gnu.org
2021-12-03 21:29 ` bergner at gcc dot gnu.org
2021-12-03 22:36 ` bergner at gcc dot gnu.org
2021-12-27 13:50 ` raoni at linux dot ibm.com
2022-02-11 19:28 ` cvs-commit at gcc dot gnu.org
2022-02-11 22:33 ` bergner at gcc dot gnu.org
2024-06-18 23:07 ` bergner at gcc dot gnu.org
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