Summary:
Reorder the condition code enum to match their encodings. Move it to MC layer so it can be used by the scheduler models.
This avoids needing an isel pattern for each condition code. And it removes
translation switches for converting between CMOV instructions and condition
codes.
Now the printer, encoder and disassembler take care of converting the immediate.
We use InstAliases to handle the assembly matching. But we print using the
asm string in the instruction definition. The instruction itself is marked
IsCodeGenOnly=1 to hide it from the assembly parser.
This does complicate the scheduler models a little since we can't assign the
A and BE instructions to a separate class now.
I plan to make similar changes for SETcc and Jcc.
Reviewers: RKSimon, spatel, lebedev.ri, andreadb, courbet
Reviewed By: RKSimon
Subscribers: gchatelet, hiraditya, kristina, lebedev.ri, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60041
llvm-svn: 357800
Previously we had a regular form of the instruction used when the immediate was 0-7. And _alt form that allowed the full 8 bit immediate. Codegen would always use the 0-7 form since the immediate was always checked to be in range. Assembly parsing would use the 0-7 form when a mnemonic like vpcomtrueb was used. If the immediate was specified directly the _alt form was used. The disassembler would prefer to use the 0-7 form instruction when the immediate was in range and the _alt form otherwise. This way disassembly would print the most readable form when possible.
The assembly parsing for things like vpcomtrueb relied on splitting the mnemonic into 3 pieces. A "vpcom" prefix, an immediate representing the "true", and a suffix of "b". The tablegenerated printing code would similarly print a "vpcom" prefix, decode the immediate into a string, and then print "b".
The _alt form on the other hand parsed and printed like any other instruction with no specialness.
With this patch we drop to one form and solve the disassembly printing issue by doing custom printing when the immediate is 0-7. The parsing code has been tweaked to turn "vpcomtrueb" into "vpcomb" and then the immediate for the "true" is inserted either before or after the other operands depending on at&t or intel syntax.
I'd rather not do the custom printing, but I tried using an InstAlias for each possible mnemonic for all 8 immediates for all 16 combinations of element size, signedness, and memory/register. The code emitted into printAliasInstr ended up checking the number of operands, the register class of each operand, and the immediate for all 256 aliases. This was repeated for both the at&t and intel printer. Despite a lot of common checks between all of the aliases, when compiled with clang at least this commonality was not well optimized. Nor do all the checks seem necessary. Since I want to do a similar thing for vcmpps/pd/ss/sd which have 32 immediate values and 3 encoding flavors, 3 register sizes, etc. This didn't seem to scale well for clang binary size. So custom printing seemed a better trade off.
I also considered just using the InstAlias for the matching and not the printing. But that seemed like it would add a lot of extra rows to the matcher table. Especially given that the 32 immediates for vpcmpps have 46 strings associated with them.
Differential Revision: https://reviews.llvm.org/D59398
llvm-svn: 356343
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
The behavior in 64-bit mode is different between Intel and AMD CPUs. Intel ignores the 0x66 prefix. AMD does not. objump doesn't ignore the 0x66 prefix. Since LLVM aims to match objdump behavior, we should do the same.
While I was trying to fix this I had change brtarget16/32 to use ENCODING_IW/ID instead of ENCODING_Iv to get the 0x66+REX.W case to act sort of sanely. It's still wrong, but that's a problem for another day.
The change in encoding exposed the fact that 16-bit mode disassembly of relative jumps was creating JMP_4 with a 2 byte immediate. It should have been JMP_2. From just printing you can't tell the difference, but if you dumped the encoding it wouldn't have matched what we started with.
While fixing that, it exposed that jo/jno opcodes were missing from the switch that this patch deleted and there were no test cases for them.
Fixes PR38537.
llvm-svn: 339622
EVEX makes heavy use of the VEX.W bit to indicate 64-bit element vs 32-bit elements. Many of the VEX instructions were split into 2 versions with different masking granularity.
The EVEX->VEX table generate can collapse the two versions if the VEX version uses is tagged as VEX_WIG. But if the VEX version is instead marked VEX.W==0 we can't combine them because we don't know if there is also a VEX version with VEX.W==1.
This patch adds a new VEX_W1X tag that indicates the EVEX instruction encodes with VEX.W==1, but is safe to convert to a VEX instruction with VEX.W==0.
This allows us to remove a bunch of manual EVEX->VEX table entries. We may want to look into splitting up the VEX_WPrefix field which would simplify the disassembler.
llvm-svn: 335017
The index size is represented by the letter after the 'v'. The number represents the memory size. If an 'x' appears after the number its means the index register can be from VR128X/VR256X instead of VR128/VR256.
As vy512mem uses a VR256X index it should have an x.
And vz256mem uses a VR512 index so it shouldn't have an x.
I admit these names kind of suck and are confusing.
llvm-svn: 334120
Previously for instructions like fxsave we would print "opaque ptr" as part of the memory operand. Now we print nothing.
We also no longer accept "opaque ptr" in the parser. We still accept any size to be specified for these instructions, but we may want to consider only parsing when no explicit size is specified. This what gas does.
llvm-svn: 331243
Remove the special casing for MRM_F8 by using HANDLE_OPTIONAL.
This should be NFC as the forms that were missing aren't used by any instructions today. They exist in the enum so that we didn't have to put them in one at a time when instructions are added. But looks like we failed here.
llvm-svn: 327298
Summary:
This patch makes the decoder understand old AMD 3DNow!
instructions that have never been properly supported in the X86
disassembler, despite being supported in other subsystems. Hopefully
this should make the X86 decoder more complete with respect to binaries
containing legacy code.
Reviewers: craig.topper
Reviewed By: craig.topper
Subscribers: llvm-commits, maksfb, bruno
Differential Revision: https://reviews.llvm.org/D43311
llvm-svn: 325295
Prior to this we had a separate instruction and register class that excluded eax to prevent matching the instruction that would encode with 0x90.
This patch changes this to just use an InstAlias to force xchgl %eax, %eax to use XCHG32rr instruction in 64-bit mode. This gets rid of the separate instruction and register class.
llvm-svn: 322532
This introduces a new operand type to encode the whether the index register should be XMM/YMM/ZMM. And new code to fixup the results created by readSIB.
This has the nice effect of removing a bunch of code that hard coded the name of every GATHER and SCATTER instruction to map the index type.
This fixes PR32807.
llvm-svn: 316273
If a method / function returns a StringRef but the
variable is of type const std::string& a temporary string is
created (StringRef has a cast operator to std::string),
which is a suboptimal behavior.
Differential revision: https://reviews.llvm.org/D34994
Test plan: make check-all
llvm-svn: 307195
Add WIG value to all of AVX instructions which ignore the W-bit in their encoding, instead of giving them the default value of 0.
This patch is needed for a follow up work on EVEX2VEX pass (replacing EVEX encoded instructions with their corresponding VEX version when possible).
Differential Revision: https://reviews.llvm.org/D29876
llvm-svn: 295643
We were frequently checking for a list of types and the different types
conveyed no real information. So lump them together explicitly.
llvm-svn: 292095
This tries to keep all the ModRM memory and register forms in their own regions of the encodings. Hoping to make it simple on some of the switch statements that operate on these encodings.
llvm-svn: 279422
Craig Topper