This commit caused -Woverloaded-virtual warnings. The two new
TargetTransformInfo::getIntImmCost functions were only added to the superclass,
and to the X86 subclass. The other targets were not updated, and the
warning highlighted this by pointing out that e.g. ARMTTI::getIntImmCost was
hiding the two new getIntImmCost variants.
We could pacify the warning by adding "using TargetTransformInfo::getIntImmCost"
to the various subclasses, or turning it off, but I suspect that it's wrong to
leave the functions unimplemnted in those targets. The default implementations
return TCC_Free, which I don't think is right e.g. for ARM.
llvm-svn: 200058
Retry commit r200022 with a fix for the build bot errors. Constant expressions
have (unlike instructions) module scope use lists and therefore may have users
in different functions. The fix is to simply ignore these out-of-function uses.
llvm-svn: 200034
This pass identifies expensive constants to hoist and coalesces them to
better prepare it for SelectionDAG-based code generation. This works around the
limitations of the basic-block-at-a-time approach.
First it scans all instructions for integer constants and calculates its
cost. If the constant can be folded into the instruction (the cost is
TCC_Free) or the cost is just a simple operation (TCC_BASIC), then we don't
consider it expensive and leave it alone. This is the default behavior and
the default implementation of getIntImmCost will always return TCC_Free.
If the cost is more than TCC_BASIC, then the integer constant can't be folded
into the instruction and it might be beneficial to hoist the constant.
Similar constants are coalesced to reduce register pressure and
materialization code.
When a constant is hoisted, it is also hidden behind a bitcast to force it to
be live-out of the basic block. Otherwise the constant would be just
duplicated and each basic block would have its own copy in the SelectionDAG.
The SelectionDAG recognizes such constants as opaque and doesn't perform
certain transformations on them, which would create a new expensive constant.
This optimization is only applied to integer constants in instructions and
simple (this means not nested) constant cast experessions. For example:
%0 = load i64* inttoptr (i64 big_constant to i64*)
Reviewed by Eric
llvm-svn: 200022
This commit teaches the X86 backend to create the same X86 instructions when it
lowers an sadd/ssub with overflow intrinsic and a conditional branch that uses
that overflow result. This allows SelectionDAG to recognize and remove one of
the redundant operations.
This fixes <rdar://problem/15874016> and <rdar://problem/15661073>.
Reviewed by Nadav
llvm-svn: 199976
scale factors in memory addresses. As it does for .att_syntax.
It was producing:
Assertion failed: (((Scale == 1 || Scale == 2 || Scale == 4 || Scale == 8)) && "Invalid scale!"), function CreateMem, file /Volumes/SandBox/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp, line 1133.
rdar://14967214
llvm-svn: 199942
when used with symbolic disassembly, add a check that the operand
is an immediate and has not been symbolicated to MCExpr operand.
I’m trying to enable the ‘C’ disassembly API option
LLVMDisassembler_Option_SetInstrComments for darwin’s
otool(1) that uses the llvm disassembler API. The problem is
that the disassembler API can change an immediate operand to
an MCExpr operand if it symbolicates it with the call backs.
And if it does the code in llvm::EmitAnyX86InstComments()
will crash when it assumes these operands are immediates.
The fix for this is very straight forward to just protect the call
to getImm() with a check of isImm(). So if the immediate for
an instruction is symbolicated it simply doesn’t get the X86
verbose assembly comments:
% otool -tV test_asm.o
test_asm.o:
(__TEXT,__text) section
_t1:
0000000000000000 vpshufd $_t1, %xmm1, %xmm0
0000000000000005 retq
0000000000000006 nopw %cs:_t1(%rax,%rax)
_t2:
0000000000000010 vpshufd $-0x1, %xmm0, %xmm0 ## xmm0 = xmm0[3,3,3,3]
0000000000000015 retq
0000000000000016 nopw %cs:_t1(%rax,%rax)
_t3:
0000000000000020 vpshufd $_t1, %xmm1, %xmm0
0000000000000025 retq
0000000000000026 nopw %cs:_t1(%rax,%rax)
_t4:
0000000000000030 vpshufd $0x2d, %xmm0, %xmm0 ## xmm0 = xmm0[1,3,2,0]
0000000000000035 retq
The fact that the immediate $0x0 is being symbolicated at
all in this case is a different problem which my next patch
will address.
rdar://10989286
llvm-svn: 199697
Add target specific rules for combining vselect dag nodes into movss/movsd
when possible.
If the vector type of the vselect dag node in input is either MVT::v4i13 or
MVT::v4f32, then try to fold according to rules:
1) fold (vselect (build_vector (0, -1, -1, -1)), A, B) -> (movss A, B)
2) fold (vselect (build_vector (-1, 0, 0, 0)), A, B) -> (movss B, A)
If the vector type of the vselect dag node in input is either MVT::v2i64 or
MVT::v2f64 (and we have SSE2), then try to fold according to rules:
3) fold (vselect (build_vector (0, -1)), A, B) -> (movsd A, B)
4) fold (vselect (build_vector (-1, 0)), A, B) -> (movsd B, A)
llvm-svn: 199683
The addition of IC_OPSIZE_ADSIZE in r198759 wasn't quite complete. It
also turns out to have been unnecessary. The disassembler handles the
AdSize prefix for itself, and doesn't care about the difference between
(e.g.) MOV8ao8 and MOB8ao8_16 definitions. So just let them coexist and
don't worry about it.
llvm-svn: 199654
The disassembler has a special case for 'L' vs. 'W' in its heuristic for
checking for 32-bit and 16-bit equivalents. We could expand the heuristic,
but better just to be consistent in using the 'L' suffix.
llvm-svn: 199652
When disassembling in 16-bit mode the meaning of the OpSize bit is
inverted. Instructions found in the IC_OPSIZE context will actually
*not* have the 0x66 prefix, and instructions in the IC context will
have the 0x66 prefix. Make use of the existing special-case handling
for the 0x66 prefix being in the wrong place, to cope with this.
llvm-svn: 199650
Aside from cleaning up the code, this also adds support for the -code16
environment and actually enables the MODE_16BIT mode that was previously
not accessible.
There is no point adding any testing for 16-bit yet though; basically
nothing will work because we aren't handling the OpSize prefix correctly
for 16-bit mode.
llvm-svn: 199649
This patch adds two new target-independent calling conventions for runtime
calls - PreserveMost and PreserveAll.
The target-specific implementation for X86-64 is defined as following:
- Arguments are passed as for the default C calling convention
- The same applies for the return value(s)
- PreserveMost preserves all GPRs - except R11
- PreserveAll preserves all GPRs and all XMMs/YMMs - except R11
Reviewed by Lang and Philip
llvm-svn: 199508
Craig Topper