llvm-6502/lib/CodeGen/SelectionDAG
Chris Lattner abd2182875 Add a simple transformation. This allows us to compile one of the inner
loops in stepanov to this:

.LBB_Z5test0PdS__2:     # no_exit.1
        fldl data(,%eax,8)
        fldl 24(%esp)
        faddp %st(1)
        fstl 24(%esp)
        incl %eax
        cmpl $2000, %eax
        fstpl 16(%esp)
        #FP_REG_KILL
        jl .LBB_Z5test0PdS__2

instead of this:

.LBB_Z5test0PdS__2:     # no_exit.1
        fldl data(,%eax,8)
        fldl 24(%esp)
        faddp %st(1)
        fstl 24(%esp)
        incl %eax
        movl $data, %ecx
        movl %ecx, %edx
        addl $16000, %edx
        subl %ecx, %edx
        movl %edx, %ecx
        sarl $2, %ecx
        shrl $29, %ecx
        addl %ecx, %edx
        sarl $3, %edx
        cmpl %edx, %eax
        fstpl 16(%esp)
        #FP_REG_KILL
        jl .LBB_Z5test0PdS__2

The old instruction selector produced:

.LBB_Z5test0PdS__2:     # no_exit.1
        fldl 24(%esp)
        faddl data(,%eax,8)
        fstl 24(%esp)
        movl %eax, %ecx
        incl %ecx
        incl %eax
        leal data+16000, %edx
        movl $data, %edi
        subl %edi, %edx
        movl %edx, %edi
        sarl $2, %edi
        shrl $29, %edi
        addl %edi, %edx
        sarl $3, %edx
        cmpl %edx, %ecx
        fstpl 16(%esp)
        #FP_REG_KILL
        jl .LBB_Z5test0PdS__2   # no_exit.1

Which is even worse!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19419 91177308-0d34-0410-b5e6-96231b3b80d8
2005-01-09 20:09:57 +00:00
..
LegalizeDAG.cpp Fix a bug legalizing call instructions (make sure to remember all result 2005-01-09 19:43:23 +00:00
Makefile Change Library Names Not To Conflict With Others When Installed 2004-10-27 23:18:45 +00:00
SelectionDAG.cpp Add a simple transformation. This allows us to compile one of the inner 2005-01-09 20:09:57 +00:00
SelectionDAGISel.cpp Handle static alloca arguments to PHI nodes. 2005-01-09 01:16:24 +00:00
TargetLowering.cpp First draft of new Target interface 2005-01-07 07:44:53 +00:00