llvm-6502/lib
Richard Sandiford b3f912b510 [SystemZ] Postpone NI->RISBG conversion to convertToThreeAddress()
r186399 aggressively used the RISBG instruction for immediate ANDs,
both because it can handle some values that AND IMMEDIATE can't,
and because it allows the destination register to be different from
the source.  I realized later while implementing the distinct-ops
support that it would be better to leave the choice up to
convertToThreeAddress() instead.  The AND IMMEDIATE form is shorter
and is less likely to be cracked.

This is a problem for 32-bit ANDs because we assume that all 32-bit
operations will leave the high word untouched, whereas RISBG used in
this way will either clear the high word or copy it from the source
register.  The patch uses the z196 instruction RISBLG for this instead.

This means that z10 will be restricted to NILL, NILH and NILF for
32-bit ANDs, but I think that should be OK for now.  Although we're
using z10 as the base architecture, the optimization work is going
to be focused more on z196 and zEC12.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187492 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-31 11:36:35 +00:00
..
Analysis Fix a severe compile time problem when forming large SCEV expressions. 2013-07-31 02:43:40 +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 Fix crashing on invalid inline asm with matching constraints. 2013-07-31 01:26:24 +00:00
DebugInfo DebugInfo: Factor out parsing compile unit DIEs to a separate function. Improve code style and comments. 2013-07-15 08:43:35 +00:00
ExecutionEngine [PowerPC] Support powerpc64le as a syntax-checking target. 2013-07-26 01:35:43 +00:00
IR Add parentheses to silence gcc warning. 2013-07-31 04:07:28 +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 MC: Support larger COFF string tables 2013-07-29 12:30:12 +00:00
Object Add support for the 's' operation to llvm-ar. 2013-07-29 12:40:31 +00:00
Option Silence gcc warning. 2013-07-22 21:29:28 +00:00
Support Fix windows' implementation of status when a file doesn't exist. 2013-07-31 00:10:25 +00:00
TableGen keep only the StringRef version of getFileOrSTDIN. 2013-06-25 05:28:34 +00:00
Target [SystemZ] Postpone NI->RISBG conversion to convertToThreeAddress() 2013-07-31 11:36:35 +00:00
Transforms Preserve fast-math flags when folding (fsub x, (fneg y)) to (fadd x, y). 2013-07-30 23:53:17 +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