[PATCH] [ASan] Improved stack overflow detection for PowerPC64

[Jay Foad]

================
Comment at: lib/asan/asan_posix.cc:61
@@ +60,3 @@
+    unsigned xo = (inst >> 1) & 0x3FF;
+    // Check for store-with-update to r1.
+    if (ra == 1 &&
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foad wrote:
> eugenis wrote:
> > It may be helpful to list or somehow characterize instructions that match this condition (I mean, there is obviously more than 1 opcode listed here).
> > 
> > I assume these "xo" checks limit it to instructions operating on SP register?
> I characterized them as "store-with-update to r1" instructions, but I will be more explicit!
opcd is "opcode" and xo is "extended opcode". These field names are taken directly from the POWER architecture manual.

http://reviews.llvm.org/D6253