XMM registers. There are many known deficiencies and fixmes, which will be
addressed ASAP. The major benefit of this work is that it will allow the
LLVM register allocator to allocate FP registers across basic blocks.
The x86 backend will still default to x87 style FP. To enable this work,
you must pass -enable-sse-scalar-fp and either -sse2 or -sse3 to llc.
An example before and after would be for:
double foo(double *P) { double Sum = 0; int i; for (i = 0; i < 1000; ++i)
Sum += P[i]; return Sum; }
The inner loop looks like the following:
x87:
.LBB_foo_1: # no_exit
fldl (%esp)
faddl (%eax,%ecx,8)
fstpl (%esp)
incl %ecx
cmpl $1000, %ecx
#FP_REG_KILL
jne .LBB_foo_1 # no_exit
SSE2:
addsd (%eax,%ecx,8), %xmm0
incl %ecx
cmpl $1000, %ecx
#FP_REG_KILL
jne .LBB_foo_1 # no_exit
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22340 91177308-0d34-0410-b5e6-96231b3b80d8
currently use: llc t.bc --filetype=obj
This will produce a t.o file which is dumpable with readelf. Currently
the file produced is empty, but the scaffolding to do more is now in place.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22292 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10446 91177308-0d34-0410-b5e6-96231b3b80d8
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. :(
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10276 91177308-0d34-0410-b5e6-96231b3b80d8
Printer::doFinalization() out in the cold. Now we pass in a TargetMachine
to Printer's constructor and get the TargetData from the TargetMachine.
Don't pass TargetMachine or MRegisterInfo objects around in the Printer.
Constify TargetData references.
X86.h: Update comment and prototype of createX86CodePrinterPass().
X86TargetMachine.cpp: Update callers of createX86CodePrinterPass().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7275 91177308-0d34-0410-b5e6-96231b3b80d8
