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Craig Topper f5465f98d2 [X86] Don't emit KTEST instructions unless only the Z flag is being used 
Summary:
KTEST has weird flag behavior. The Z flag is set for all bits in the AND of the k-registers being 0, and the C flag is set for all bits being 1. All other flags are cleared.

We currently emit this instruction in EmitTEST and don't check the condition code. This can lead to strange things like using the S flag after a KTEST for a signed compare.

The domain reassignment pass can also transform TEST instructions into KTEST and is not protected against the flag usage either. For now I've disabled this part of the domain reassignment pass. I tried to comment out the checks in the mir test so that we could recover them later, but I couldn't figure out how to get that to work.

This patch moves the KTEST handling into LowerSETCC and now creates a ktest+x86setcc. I've chosen this approach because I'd like to add support for the C flag for all ones in a followup patch. To do that requires that I can rewrite the condition code going in the x86setcc to be different than the original SETCC condition code.

This fixes PR36182. I'll file a PR to fix domain reassignment once this goes in. Should this be merged to 6.0?

Reviewers: spatel, guyblank, RKSimon, zvi

Reviewed By: guyblank

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42770

llvm-svn: 324576
 		2018-02-08 07:45:55 +00:00
clang [clang-format] Set ObjCBinPackProtocolList to Never for google style 2018-02-08 01:49:10 +00:00
clang-tools-extra Resubmit "[clangd] The new threading implementation" 2018-02-08 07:37:35 +00:00
compiler-rt Update test counter_promo_nest.c to meet llvm change 2018-02-08 07:15:49 +00:00
debuginfo-tests [debuginfo-tests] Support moving debuginfo-tests to llvm/projects 2017-12-12 16:54:20 +00:00
libclc Add vstore_half_rte implementation 2018-02-06 18:44:50 +00:00
libcxx Temporarily comment out deduction guide tests while I figure out what to do with old bots 2018-02-08 07:20:45 +00:00
libcxxabi Fix compilation in C++17 mode. 2018-02-07 23:23:23 +00:00
libunwind [cmake] [libunwind] LLVM_FOUND isn't always set, so just test if 2018-01-27 19:31:44 +00:00
lld Symbols defined in linker scripts should not have dso_local flag set in LTO resolutions. 2018-02-08 04:25:52 +00:00
lldb [docs] Update docs for cmake options LLDB_TEST_C_COMPILER and LLDB_TEST_CXX_COMPILER 2018-02-08 05:11:17 +00:00
llgo irgen: Create functions instead of global variables for builtin hash and equal algorithms. 2017-06-04 22:11:28 +00:00
llvm [X86] Don't emit KTEST instructions unless only the Z flag is being used 2018-02-08 07:45:55 +00:00
openmp [OpenMP][libomptarget] Add data sharing support in libomptarget 2018-02-07 18:21:55 +00:00
parallel-libs [Axccel] Remove -Wno-missing-braces in build 2016-12-19 21:34:07 +00:00
polly [ScopBuilder] Make -polly-stmt-granularity=scalar-indep the default. 2018-02-03 06:59:47 +00:00
README.md Add an svn project to contain the files that appear at the root of the 2017-10-19 21:09:49 +00:00

README.md

Low Level Virtual Machine (LLVM)

This directory and its subdirectories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments.