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Sanjay Patel d31220e0de [x86] promote all multiply i8 by constant to i32 
We have these 2 "isDesirable" promotion hooks (I'm not sure why we need both of them, but that's 
independent of this patch), and we can adjust them to promote "mul i8 X, C" to i32. Then, all of 
our existing LEA and other multiply expansion magic happens as it would for i32 ops.

Some of the test diffs show that we could end up with an actual 32-bit mul instruction here 
because we choose not to expand to simpler ops. That instruction could be slower depending on the 
subtarget. On the plus side, this means we don't need a separate instruction to load the constant 
operand and possibly an extra instruction to move the result. If we need to tune mul i32 further, 
we could add a later transform that tries to shrink it back to i8 based on subtarget timing.

I did not bother to duplicate all of the 32-bit test file RUNs and target settings that exist to 
test whether LEA expansion is cheap or not. The diffs here assume a default target, so that means 
LEA is generally cheap.

Differential Revision: https://reviews.llvm.org/D54803

llvm-svn: 347557
 		2018-11-26 15:22:30 +00:00
clang [PowerPC] Vector load/store builtins overstate alignment of pointers 2018-11-26 14:35:38 +00:00
clang-tools-extra [clangd] Fix missing include from r347538 - fix windows buildbots 2018-11-26 13:35:02 +00:00
compiler-rt [X86][compiler-rt] Add missing semicolon 2018-11-24 20:57:03 +00:00
debuginfo-tests Set config.lit_tools_dir, which is needed by lit.llvm.initialize. 2018-11-06 21:54:27 +00:00
libclc r600: Add datalayout to image builtin implementation 2018-11-10 21:43:40 +00:00
libcxx [NFC] Fix typo in comment 2018-11-22 19:10:28 +00:00
libcxxabi [CMake] Passthrough CFLAGS when checking the compiler-rt path 2018-11-14 00:09:26 +00:00
libunwind [CMake] Passthrough CFLAGS when checking the compiler-rt path 2018-11-14 00:09:26 +00:00
lld [LLD][ELF] - Added a test for "-image-base: number expected" message. NFC. 2018-11-26 13:15:57 +00:00
lldb Revert r347491 as it's llvm counterpart breaks buildbots 2018-11-23 17:13:47 +00:00
llgo Update copyright year to 2018. 2018-06-18 12:22:17 +00:00
llvm [x86] promote all multiply i8 by constant to i32 2018-11-26 15:22:30 +00:00
openmp [OPENMP][NVPTX]Improved lock/critical constructs. 2018-11-20 20:19:36 +00:00
parallel-libs Update copyright year to 2018. 2018-06-18 12:22:17 +00:00
polly [CMake] Fix generation of exported targets in build directory 2018-11-06 15:18:17 +00:00
README.md Update the project name in README.md 2018-10-19 00:03:01 +00:00

README.md

The LLVM Compiler Infrastructure

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