llvm-6502/lib
Richard Sandiford 8c20158fb0 [SystemZ] Use SRST to optimize memchr
SystemZTargetLowering::emitStringWrapper() previously loaded the character
into R0 before the loop and made R0 live on entry.  I'd forgotten that
allocatable registers weren't allowed to be live across blocks at this stage,
and it confused LiveVariables enough to cause a miscompilation of f3 in
memchr-02.ll.

This patch instead loads R0 in the loop and leaves LICM to hoist it
after RA.  This is actually what I'd tried originally, but I went for
the manual optimisation after noticing that R0 often wasn't being hoisted.
This bug forced me to go back and look at why, now fixed as r188774.

We should also try to optimize null checks so that they test the CC result
of the SRST directly.  The select between null and the SRST GPR result could
then usually be deleted as dead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188779 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-20 09:38:48 +00:00
..
Analysis Fix assert with GEP ptr vector indexing structs 2013-08-19 21:43:16 +00:00
AsmParser Target/X86: Add explicit Win64 and System V/x86-64 calling conventions. 2013-07-12 06:02:35 +00:00
Bitcode Make .bc en/decoding of AttrKind stable 2013-07-26 04:16:55 +00:00
CodeGen [SystemZ] Use SRST to optimize memchr 2013-08-20 09:38:48 +00:00
DebugInfo llvm-dwarfdump: Do not include address offsets for attributes, only for tags 2013-08-19 03:36:23 +00:00
ExecutionEngine memcmp is not a valid way to compare structs with padding in them. 2013-08-20 09:27:31 +00:00
IR Introduce non-const overloads for GlobalAlias::{get,resolve}AliasedGlobal. 2013-08-19 23:13:33 +00:00
IRReader Add 'const' qualifiers to static const char* variables. 2013-07-16 01:17:10 +00:00
Linker Extend RemapInstruction and friends to take an optional new parameter, a ValueMaterializer. 2013-05-28 15:17:05 +00:00
MC Support C99 hexadecimal floating-point literals in assembly 2013-08-14 14:23:31 +00:00
Object Add back missing PPC relocation types. 2013-08-09 09:42:14 +00:00
Option Options: explicit handling of -- 2013-08-13 22:23:05 +00:00
Support Go through the really awkward dance required to delete the memory 2013-08-18 01:20:32 +00:00
TableGen Add an error check for a typo I accidentally made in a td file that caused an assert to fire. 2013-08-20 04:22:09 +00:00
Target [SystemZ] Use SRST to optimize memchr 2013-08-20 09:38:48 +00:00
Transforms Add a llvm.copysign intrinsic 2013-08-19 23:35:46 +00:00
CMakeLists.txt Move lib/Archive to tools/llvm-ar. 2013-06-17 15:47:20 +00:00
LLVMBuild.txt Move lib/Archive to tools/llvm-ar. 2013-06-17 15:47:20 +00:00
Makefile Move lib/Archive to tools/llvm-ar. 2013-06-17 15:47:20 +00:00