llvm-project/llvm
Richard Sandiford 35ec4e356c [SystemZ] Add instruction-shortening pass
When loading immediates into a GR32, the port prefered LHI, followed by
LLILH or LLILL, followed by IILF.  LHI and IILF are natural 32-bit
operations, but LLILH and LLILL also clear the upper 32 bits of the register.
This was represented as taking a 32-bit subreg of a 64-bit assignment.

Using subregs for something as simple as a move immediate was probably
a bad idea.  Also, I have patches to add support for the high-word facility, 
and we don't want something like LLILH and LLILL to stop the high word of
the same GPR from being used.

This patch therefore uses LHI and IILF to begin with and adds a late
machine-specific pass to use LLILH and LLILL if the other half of the
register is not live.  The high-word patches extend this behavior to
IIHF, LLIHL and LLIHH.

No behavioral change intended.

llvm-svn: 191363
2013-09-25 10:11:07 +00:00
..
autoconf Remove error output from configure if CFLAGS is set (r174313). 2013-09-24 11:38:45 +00:00
bindings [python-bindings] Added support for getting/setting operands of values and getting the number of operands of a value. 2013-09-11 01:38:12 +00:00
cmake [CMake] Hack GetSVN.cmake to handle unusual terminals. 2013-09-16 21:38:01 +00:00
docs Add a paragraph on prefix data layout. 2013-09-23 20:14:21 +00:00
examples ExceptionDemo.cpp: Tweak a @param. [-Wdocumentation] 2013-07-29 11:03:50 +00:00
include MC: Remove vestigial PCSymbol field from AsmInfo 2013-09-25 09:36:11 +00:00
lib [SystemZ] Add instruction-shortening pass 2013-09-25 10:11:07 +00:00
projects Port the detection of zlib from the main autoconf system to the sample 2013-08-18 01:55:15 +00:00
runtime Bring back the build of libprofile_rt on Sparc. It is now working correctly. See: 2013-09-08 09:15:09 +00:00
test [PR16882] Ignore noreturn definitions when setting isPhysRegUsed. 2013-09-25 00:26:17 +00:00
tools Move LTO support library to a component, allowing it to be tested 2013-09-24 23:52:22 +00:00
unittests Fixed typo in CreateProcessTrailingSlash test 2013-09-20 18:21:59 +00:00
utils Fix doxygen comments to use correct function name. 2013-09-25 06:40:22 +00:00
.arcconfig
.clang-format Add a clang-format file so that the tool can automatically detect the 2013-09-02 07:19:04 +00:00
.gitignore
CMakeLists.txt [conf] Add config variable to disable crash related overrides. 2013-08-30 20:39:21 +00:00
CODE_OWNERS.TXT Add more owners to CODE_OWNERS.TXT (Kostya Serebryany: AddressSanitizer and ThreadSanitizer; Evgeniy Stepanov: MemorySanitizer) 2013-06-27 08:47:12 +00:00
CREDITS.TXT Test commit. 2013-08-16 18:09:06 +00:00
LICENSE.TXT Be more specific and capitalize filenames. 2013-05-21 21:22:34 +00:00
LLVMBuild.txt
Makefile Fix regular expression used by 'make update' to only look for 'I' and '?' at the start of svn info results and to check for spaces after 'I' instead of just after '?'. 2013-07-03 14:48:37 +00:00
Makefile.common
Makefile.config.in Add an autoconf option for turning on -gsplit-dwarf by default 2013-06-25 01:12:25 +00:00
Makefile.rules Makefile.rules: Avoid -fomit-frame-pointer also on cygwin due to PR14646. 2013-08-18 03:38:40 +00:00
README.txt
configure Remove error output from configure if CFLAGS is set (r174313). 2013-09-24 11:38:45 +00:00
llvm.spec.in

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