[PATCH] ARM Unwind syntax in libcxxabi

Renato Golin renato.golin at linaro.org
Sun Sep 7 11:46:56 PDT 2014

Comment at: src/Unwind/UnwindRegistersRestore.S:329
@@ -328,3 +328,3 @@
   ldr lr, [lr, #60]  @ restore pc into lr
-#if _ARM_ARCH > 4
+#if __ARM_ARCH > 4
   bx lr
compnerd wrote:
> Wow.  Did this even work previously?  This feels like it could be split out into a separate patch to first address use of the branch on ARM v4.
No, it didn't. :)

I thought about a separate patch, but it was so small that I didn't bother. I can just commit that one and discuss the rest of the patch.

Comment at: src/Unwind/UnwindRegistersRestore.S:368
@@ +367,3 @@
+  vldmia r0, {d0-d15} @ fldmiax is deprecated in ARMv7+ and now behaves like vldmia
compnerd wrote:
> Why the comment here but not previously?  Im not sure it really adds much.  However, I would say that the comment indicating that fldmiax is equivalent to the ldc is more useful and it may be nice to restore those.
I'll keep the old comment.

The new comment helps understand why I have done all three alternatives as vldmia, and that's because they're all the same on v7+, but didn't use to be up to v6. The main difference is the 0x21 instead of 0x20, which on v7+ they're all the same.


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