instruction selector by adding a new pseudo-instruction
FP_REG_KILL. This instruction implicitly defines all x86 fp registers
and is a terminator so that passes which add machine code at the end
of basic blocks (like phi elimination) do not add instructions between
it and the branch or return instruction.
llvm-svn: 10562
a) remove opIsUse(), opIsDefOnly(), opIsDefAndUse()
b) add isUse(), isDef()
c) rename opHiBits32() to isHiBits32(),
opLoBits32() to isLoBits32(),
opHiBits64() to isHiBits64(),
opLoBits64() to isLoBits64().
This results to much more readable code, for example compare
"op.opIsDef() || op.opIsDefAndUse()" to "op.isDef()" a pattern used
very often in the code.
llvm-svn: 10461
allocaton on the X86 to add information to the machine code denoting
that our floating point stackifier cannot handle virtual point
register that are alive across basic blocks. This pass adds an
implicit def of all virtual floating point register at the end of each
basic block.
llvm-svn: 10446
Eventually this pass will provide substantially better code in the interim between when we
have a crappy isel and nice isel. Unfortunately doing so requires fixing the backend to
actually SUPPORT all of the fancy addressing modes that we now generate, and writing a DCE
pass for machine code. Each of these is a fairly substantial job, so this will remain disabled
for the immediate future. :(
llvm-svn: 10276
folding of instructions into addressing modes. This creates lots of dead
instructions, which are currently not deleted. It also creates a lot of
instructions that the X86 backend currently cannot handle. :(
llvm-svn: 10275
return the number of instructions added to/removed from the basic block
passed as their first argument.
Note: This is only needed because we use a std::vector instead of an
ilist to keep MachineBasicBlock instructions. Inserting an instruction
to a MachineBasicBlock invalidates all iterators to the basic
block. The return value can be used to update an index to the machine
basic block instruction vector and circumvent the iterator elimination
problem but this is really not needed if we move to a better
representation.
llvm-svn: 9704
strings with the stuff that used to print to an ostream directly. We now NEVER build
up big strings, only to print them once they are formed.
llvm-svn: 9686
C is a constant which can be sign-extended from 8 bits without value loss,
and op is one of: add, sub, imul, and, or, xor.
This allows the JIT to emit the one byte version of the constant instead of
the two or 4 byte version. Because these instructions are very common, this
can save a LOT of code space. For example, I sampled two benchmarks, 176.gcc
and 254.gap.
BM Old New Reduction
176.gcc 2673621 2548962 4.89%
254.gap 498261 475104 4.87%
Note that while the percentage is not spectacular, this did eliminate
124.6 _KILOBYTES_ of codespace from gcc. Not bad.
Note that this doesn't effect the llc version at all, because the assembler
already does this optimization.
llvm-svn: 9284
getelementptr code path for use by other code paths (like malloc and alloca).
* Optimize comparisons with zero
* Generate neg, not, inc, and dec instructions, when possible.
This gives some code size wins, which might translate into performance. We'll
see tommorow in the nightly tester.
llvm-svn: 9267
