llvm-project/llvm
Davide Italiano 824d695231 [SCCP] Teach the pass about `mul %x 0` even if %x is overdefined.
The motivating example is:

extern int patatino;
int goo() {
    int x = 0;
    for (int i = 0; i < 1000000; ++i) {
        x *= patatino;
    }
    return x;
}

Currently SCCP will not realize that this function returns always zero,
therefore will try to unroll and vectorize the loop at -O3 producing an
awful lot of (useless) code. With this change, it will just produce:

0000000000000000 <g>:
   xor    %eax,%eax
   retq

llvm-svn: 289175
2016-12-09 03:08:42 +00:00
..
bindings Fix go binding to adapt the new attribute API 2016-11-18 10:11:02 +00:00
cmake [CMake] Add check for HAVE_CRASHREPORTER_INFO 2016-12-07 20:55:38 +00:00
docs IR, X86: Understand !absolute_symbol metadata on global variables. 2016-12-08 19:01:00 +00:00
examples Prune unused libdeps. 2016-12-08 15:28:02 +00:00
include [LCG] Minor cleanup to the LCG walk over a function, NFC. 2016-12-09 00:46:44 +00:00
lib [SCCP] Teach the pass about `mul %x 0` even if %x is overdefined. 2016-12-09 03:08:42 +00:00
projects
resources
runtimes [CMake] Make the runtimes directory work with bootstrap builds 2016-10-19 21:50:25 +00:00
test [SCCP] Teach the pass about `mul %x 0` even if %x is overdefined. 2016-12-09 03:08:42 +00:00
tools [ObjectYAML] Support for DWARF debug_aranges 2016-12-09 00:26:44 +00:00
unittests Fix ASAN buildbots by fixing a double free crash. 2016-12-08 16:57:04 +00:00
utils Summary: Currently there is no way to disable deprecated warning from asm like this 2016-12-05 23:55:13 +00:00
.arcconfig
.clang-format
.clang-tidy
.gitignore
CMakeLists.txt [CMake] Fixing clang standalone build 2016-12-06 17:09:29 +00:00
CODE_OWNERS.TXT CODE_OWNERS: Take ownership of IR Linker as discussed on llvm-dev 2016-12-02 14:06:53 +00:00
CREDITS.TXT Test Commit, removing a blank line in CREDITS.TXT 2016-11-24 15:40:19 +00:00
LICENSE.TXT
LLVMBuild.txt
README.txt Test commit, deleted empty line at the end of README.txt 2016-11-07 18:31:21 +00:00
RELEASE_TESTERS.TXT
configure
llvm.spec.in

README.txt

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