This is a followup from:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150323/268067.html
Upgrade instructions:
$ mv llvm/include/llvm/Config/config.h ./config.h.BACKUP
# copy the configure line from line 7 of llvm/config.log
# (for example: `$ ./configure --no-create --no-recursion`)
$ mkdir build
$ cd build
# run the configure line, but this time with '../llvm' at the beginning:
$ ../llvm/configure --no-create --no-recursion
These warnings will soon be turned into hard errors after a week. Speak up now
if this is going to be a problem for you.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236399 91177308-0d34-0410-b5e6-96231b3b80d8
So there are a couple of issues with indirect calls on thumbv4t. First, the most
'obvious' instruction, 'blx' isn't available until v5t. And secondly, the
next-most-obvious sequence: 'mov lr, pc; bx rN' doesn't DTRT in thumb code
because the saved off pc has its thumb bit cleared, so when the callee returns
we end up in ARM mode.... yuck.
The solution is to 'bl' to a nearby landing pad with a 'bx rN' in it.
We could cut down on code size by sharing the landing pads between call sites
that are close enough, but for the moment let's do correctness first and look at
performance later.
Patch by: Iain Sandoe
http://reviews.llvm.org/D6519
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223380 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts r214893, re-applying r214881 with the test case relaxed a bit to
satiate the build bots.
POP on armv4t cannot be used to change thumb state (unilke later non-m-class
architectures), therefore we need a different return sequence that uses 'bx'
instead:
POP {r3}
ADD sp, #offset
BX r3
This patch also fixes an issue where the return value in r3 would get clobbered
for functions that return 128 bits of data. In that case, we generate this
sequence instead:
MOV ip, r3
POP {r3}
ADD sp, #offset
MOV lr, r3
MOV r3, ip
BX lr
http://reviews.llvm.org/D4748
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214928 91177308-0d34-0410-b5e6-96231b3b80d8
POP on armv4t cannot be used to change thumb state (unilke later non-m-class
architectures), therefore we need a different return sequence that uses 'bx'
instead:
POP {r3}
ADD sp, #offset
BX r3
This patch also fixes an issue where the return value in r3 would get clobbered
for functions that return 128 bits of data. In that case, we generate this
sequence instead:
MOV ip, r3
POP {r3}
ADD sp, #offset
MOV lr, r3
MOV r3, ip
BX lr
http://reviews.llvm.org/D4748
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214881 91177308-0d34-0410-b5e6-96231b3b80d8
Jonathan Roelofs