The problem this patch addresses is the handling of register tie
constraints in AsmMatcherEmitter, where one operand is tied to a
sub-operand of another operand. The typical scenario for this to
happen is the tie between the "write-back" register of a pre-inc
instruction, and the base register sub-operand of the memory address
operand of that instruction.
The current AsmMatcherEmitter code attempts to handle tied
operands by emitting the operand as usual first, and emitting
a CVT_Tied node when handling the second (tied) operand. However,
this really only works correctly if the tied operand does not
have sub-operands (and isn't a sub-operand itself). Under those
circumstances, a wrong MC operand list is generated.
In discussions with Jim Grosbach, it turned out that the MC operand
list really ought not to contain tied operands in the first place;
instead, it ought to consist of exactly those operands that are
named in the AsmString. However, getting there requires significant
rework of (some) targets.
This patch fixes the immediate problem, and at the same time makes
one (small) step in the direction of the long-term solution, by
implementing two changes:
1. Restricts the AsmMatcherEmitter handling of tied operands to
apply solely to simple operands (not complex operands or
sub-operand of such).
This means that at least we don't get silently corrupt MC operand
lists as output. However, if we do have tied sub-operands, they
would now no longer be handled at all, except for:
2. If we have an operand that does not occur in the AsmString,
and also isn't handled as tied operand, simply emit a dummy
MC operand (constant 0).
This works as long as target code never attempts to access
MC operands that do no not occur in the AsmString (and are
not tied simple operands), which happens to be the case for
all targets where this situation can occur (ARM and PowerPC).
[ Note that this change means that many of the ARM custom
converters are now superfluous, since the implement the
same "hack" now performed already by common code. ]
Longer term, we ought to fix targets to never access *any*
MC operand that does not occur in the AsmString (including
tied simple operands), and then finally completely remove
all such operands from the MC operand list.
Patch approved by Jim Grosbach.
llvm-svn: 180677
variant/dialect. Addresses a FIXME in the emitMnemonicAliases function.
Use and test case to come shortly.
rdar://13688439 and part of PR13340.
llvm-svn: 179804
For example, ARM has several instructions with a literal '#0' immediate in the syntax
that's not represented as an actual operand. The asm matcher is expected a token
operand, but the parser will have created an immediate operand. This is currently
handled by dedicated per-instruction C++ munging of the ParsedAsmOperand list, but
will be better handled by this hook.
llvm-svn: 174487
// FIXME: Constraints are hard coded to 'm', but we need an 'r'
// constraint for addressof. This needs to be cleaned up!
Test cases are already in place. Specifically,
clang/test/CodeGen/ms-inline-asm.c t15(), t16(), and t24().
llvm-svn: 172569
The purpose of this patch is to allow PredicateMethods to be set to something
like "isUImm<8>", calling a C++ template method to reduce code duplication. For
this to work, the PredicateMethod must be mangled into a valid C++ identifier
for insertion into an enum.
llvm-svn: 172073
Most places can use PrintFatalError as the unwinding mechanism was not
used for anything other than printing the error. The single exception
was CodeGenDAGPatterns.cpp, where intermediate errors during type
resolution were ignored to simplify incremental platform development.
This use is replaced by an error flag in TreePattern and bailout earlier
in various places if it is set.
llvm-svn: 166712
Some of these dyn_cast<>'s would be better phrased as isa<> or cast<>.
That will happen in a future patch.
There are also two dyn_cast_or_null<>'s slipped in instead of
dyn_cast<>'s, since they were causing crashes with just dyn_cast<>.
llvm-svn: 165646
map constraints and MCInst operands to inline asm operands. This replaces the
getMCInstOperandNum() function.
The logic to determine the constraints are not in place, so we still default to
a register constraint (i.e., "r"). Also, we no longer build the MCInst but
rather return just the opcode to get the MCInstrDesc.
llvm-svn: 164979
MatchInstructionImpl() function.
These values are used by the ConvertToMCInst() function to index into the
ConversionTable. The values are also needed to call the GetMCInstOperandNum()
function.
llvm-svn: 163101
AsmMatcherEmitter. This function maps inline assembly operands to MCInst
operands.
For example, '__asm mov j, eax' is represented by the follow MCInst:
<MCInst 1460 <MCOperand Reg:0> <MCOperand Imm:1> <MCOperand Reg:0>
<MCOperand Expr:(j)> <MCOperand Reg:0> <MCOperand Reg:43>>
The first 5 MCInst operands are a result of j matching as a memory operand
consisting of a BaseReg (Reg:0), MemScale (Imm:1), MemIndexReg(Reg:0),
Expr (Expr:(j), and a MemSegReg (Reg:0). The 6th MCInst operand represents
the eax register (Reg:43).
This translation is necessary to determine the Input and Output Exprs. If a
single asm operand maps to multiple MCInst operands, the index of the first
MCInst operand is returned. Ideally, it would return the operand we really
care out (i.e., the Expr:(j) in this case), but I haven't found an easy way
of doing this yet.
llvm-svn: 162920
Adding arbitrary records to ARM.td would break
basic-arm-instructions.s because selection of nop vs mov r0,r0 was
ambiguous (this will be tested by a subsequent addition to ARM.td).
An imperfect but sensible fix is to give precedence to match rules
that have more constraints.
llvm-svn: 162824
When reporting an error for a defm, we would previously only report the
location of the outer defm, which is not always where the error is.
Now we also print the location of the expanded multiclass defs:
lib/Target/X86/X86InstrSSE.td:2902:12: error: foo
defm ADD : basic_sse12_fp_binop_s<0x58, "add", fadd, SSE_ALU_ITINS_S>,
^
lib/Target/X86/X86InstrSSE.td:2801:11: note: instantiated from multiclass
defm PD : sse12_fp_packed<opc, !strconcat(OpcodeStr, "pd"), OpNode, VR128,
^
lib/Target/X86/X86InstrSSE.td:194:5: note: instantiated from multiclass
def rm : PI<opc, MRMSrcMem, (outs RC:$dst), (ins RC:$src1, x86memop:$src2),
^
llvm-svn: 162409
No change in interface or functionality. Purely under-the-hood
details of the generated function that change.
The X86 assembly parser is reduced in size by over 15% and ARM by
over 10%.
No performance change by my measurements.
llvm-svn: 162337
Make sure the tblgen'erated asm matcher correctly returns numoperands+1
as the ErrorInfo when the problem was that there weren't enough operands
specified.
rdar://9142751
llvm-svn: 160144
Ulrich Weigand