There are cases of AVX-512 instructions that have two possible encodings. This is the case with instructions that use vector registers with low indexes of 0 - 15 and do not use the zmm registers or the mask k registers.
The EVEX encoding prefix requires 4 bytes whereas the VEX prefix can take only up to 3 bytes. Consequently, using the VEX encoding for these instructions results in a code size reduction of ~2 bytes even though it is compiled with the AVX-512 features enabled.
Reviewers: Craig Topper, Zvi Rackoover, Elena Demikhovsky
Differential Revision: https://reviews.llvm.org/D27901
llvm-svn: 290663
an immediate operand when we don't have instruction-specific comments.
This ensures that instruction-specific comments are attached to the same
line as the instruction which is important for using them to write
readable and maintainable tests. My next commit will just such a test.
llvm-svn: 217099
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)
Changes made by clang-tidy with minor tweaks.
llvm-svn: 215558
been MC-ized for assembly printing. MSP430 is mostly so, but still has the
asm printer and lowering code in the printer subdir for the moment.
llvm-svn: 115360
Gadi Haber