RPCS3/llvm
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm.git synced 2024-12-11 21:56:15 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

[TableGen] AsmMatcher: fix OpIdx computation when HasOptionalOperands is true

Browse Source 
Consider the following instruction: "inst.eq $dst, $src" where ".eq"
is an optional flag operand.  The $src and $dst operands are
registers.  If we parse the instruction "inst r0, r1", the flag is not
present and it will be marked in the "OptionalOperandsMask" variable.
After the matching is complete we call the "convertToMCInst" method.

The current implementation works only if the optional operands are at
the end of the array.  The "Operands" array looks like [token:"inst",
reg:r0, reg:r1].  The first operand that must be added to the MCInst
is the destination, the r0 register.  The "OpIdx" (in the Operands
array) for this register is 2.  However, since the flag is not present
in the Operands, the actual index for r0 should be 1.  The flag is not
present since we rely on the default value.

This patch removes the "NumDefaults" variable and replaces it with an
array (DefaultsOffset).  This array contains an index for each operand
(excluding the mnemonic).  At each index, the array contains the
number of optional operands that should be subtracted.  For the
previous example, this array looks like this: [0, 1, 1].  When we need
to access the r0 register, we compute its index as 2 -
DefaultsOffset[1] = 1.

Patch by Alexandru Guduleasa!

Reviewers: SamWot, nhaustov, niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D35998

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@309949 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nirav Dave 2017-08-03 15:40:21 +00:00
parent 9360b2e1ac
commit 53e7817cd8
1 changed files with 19 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
utils/TableGen/AsmMatcherEmitter.cpp
View File

@ -1847,13 +1847,30 @@ static void emitConvertFuncs(CodeGenTarget &Target, StringRef ClassName,
CvtOS << " assert(Kind < CVT_NUM_SIGNATURES && \"Invalid signature!\");\n";
CvtOS << " const uint8_t *Converter = ConversionTable[Kind];\n";
if (HasOptionalOperands) {
CvtOS << " unsigned NumDefaults = 0;\n";
size_t MaxNumOperands = 0;
for (const auto &MI : Infos) {
MaxNumOperands = std::max(MaxNumOperands, MI->AsmOperands.size());
}
CvtOS << " unsigned DefaultsOffset[" << (MaxNumOperands) << "];\n";
CvtOS << " assert(OptionalOperandsMask.size() == " << (MaxNumOperands)
<< ");\n";
CvtOS << " for (unsigned i = 0, NumDefaults = 0; i < " << (MaxNumOperands)
<< "; ++i) {\n";
CvtOS << " DefaultsOffset[i] = NumDefaults;\n";
CvtOS << " NumDefaults += (OptionalOperandsMask[i] ? 1 : 0);\n";
CvtOS << " }\n";
}
CvtOS << " unsigned OpIdx;\n";
CvtOS << " Inst.setOpcode(Opcode);\n";
CvtOS << " for (const uint8_t *p = Converter; *p; p+= 2) {\n";
if (HasOptionalOperands) {
CvtOS << " OpIdx = *(p + 1) - NumDefaults;\n";
// OpIdx has different semantics for Tied operands and the rest of the
// operands. For Tied it is the index in the Inst, therefore we use it
// directly. For the rest of the operands, we need to account for the
// offset.
CvtOS << " OpIdx = *(p + 1);\n";
CvtOS << " OpIdx -= (*p != CVT_Tied) ? DefaultsOffset[*(p + 1) - 1] : "
"0;\n";
} else {
CvtOS << " OpIdx = *(p + 1);\n";
}
@ -1988,7 +2005,6 @@ static void emitConvertFuncs(CodeGenTarget &Target, StringRef ClassName,
<< " " << Op.Class->DefaultMethod << "()"
<< "->" << Op.Class->RenderMethod << "(Inst, "
<< OpInfo.MINumOperands << ");\n"
<< " ++NumDefaults;\n"
<< " } else {\n"
<< " static_cast<" << TargetOperandClass
<< "&>(*Operands[OpIdx])." << Op.Class->RenderMethod