kris/boringssl
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Clarify toc@ha and offsets.

Browse Source 
At first I thought something was wrong, but some experiments with GCC
and digging into relocation definitions confirmed things were fine. In
doing so, tweak the comments so the offset is written more clearly. Both
offset+foo@toc@l and foo@toc@l+offset bind apply the @l after adding the
offset, but it's slightly less confusing with the former spelling.

Change-Id: I43b2c0b8855f64ac6ca4d95ae85bec680a19bc1c
Reviewed-on: https://boringssl-review.googlesource.com/16705
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This commit is contained in:
David Benjamin 2017-05-30 14:35:53 -04:00 committed by CQ bot account: commit-bot@chromium.org
parent 7f07fb2b5a
commit 592af53963
1 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
util/fipstools/delocate.go
View File

@ -643,6 +643,14 @@ Args:
// this by unconditionally erasing the toc@ha
// instructions and doing the full lookup when
// processing toc@l.
//
// Note that any offset here applies before @ha
// and @l. That is, 42+foo@toc@ha is
// #ha(42+foo-.TOC.), not 42+#ha(foo-.TOC.). Any
// corresponding toc@l references are required
// by the ABI to have the same offset. The
// offset will be incorporated in full when
// those are processed.
if instructionName != "addis" || len(argNodes) != 3 || i != 2 || args[1] != "2" {
return nil, errors.New("can't process toc@ha reference")
}
@ -668,7 +676,7 @@ Args:
switch instructionName {
case "addi":
// The original instruction was:
// addi destReg, tocHaReg, symbol@toc@l+offset
// addi destReg, tocHaReg, offset+symbol@toc@l
//
// All that is left is adding the offset, if any.
instructionName = ""
@ -679,7 +687,7 @@ Args:
}
case "ld", "lhz", "lwz":
// The original instruction was:
// l?? destReg, symbol@toc@l+offset(tocHaReg)
// l?? destReg, offset+symbol@toc@l(tocHaReg)
//
// We transform that into the
// equivalent dereference of destReg: