llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-10 02:36:06 +00:00

History

Chris Lattner ffddf6ba1c Enable deleting branches to successor blocks. With the previous patches,

branch folding can now compile stuff like this:

void foo(int W, int X, int Y, int Z) {
  if (W & 1) {
    for (; X;--X) bar();
  } else if (W & 2) {
    for (; Y;--Y) bar();
  } else if (W & 4) {
    for (; Z;--Z) bar();
  } else if (W & 8) {
    for (; W;--W) bar();
  }

  if (W) {
    bar();
  }
}

contrived testcase where loops exits all end up merging together.  To have
the loop merges be:

...
        cmplw cr0, r30, r27
        bne cr0, LBB1_14        ;bb38
LBB1_16:        ;cond_next48.loopexit
        mr r27, r29
LBB1_20:        ;cond_next48
        cmplwi cr0, r27, 0
        beq cr0, LBB1_22        ;UnifiedReturnBlock
...

instead of:


...
        cmplw cr0, r30, r27
        bne cr0, LBB1_14        ;bb38
LBB1_16:        ;cond_next48.loopexit
        mr r27, r29
        b LBB1_20       ;cond_next48
LBB1_17:        ;cond_next48.loopexit1
        b LBB1_20       ;cond_next48
LBB1_18:        ;cond_next48.loopexit2
        b LBB1_20       ;cond_next48
LBB1_19:        ;cond_next48.loopexit3
LBB1_20:        ;cond_next48
        cmplwi cr0, r27, 0
        beq cr0, LBB1_22        ;UnifiedReturnBlock
...


This is CodeGen/PowerPC/branch-opt.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31006 91177308-0d34-0410-b5e6-96231b3b80d8

2006-10-17 18:16:40 +00:00

SelectionDAG

Make sure operand does have size and element type operands.

2006-10-17 17:06:35 +00:00

AsmPrinter.cpp

Clean up interface to getGlobalLinkName.

2006-10-17 17:17:24 +00:00

BranchFolding.cpp

Enable deleting branches to successor blocks. With the previous patches,

2006-10-17 18:16:40 +00:00

DwarfWriter.cpp

Clean up interface to getGlobalLinkName.