Turn conditions like x<Y|z==q into multiple blocks.

This compiles Regression/CodeGen/X86/or-branch.ll into:

_foo:
        subl $12, %esp
        call L_bar$stub
        movl 20(%esp), %eax
        movl 16(%esp), %ecx
        cmpl $5, %eax
        jl LBB1_1       #cond_true
LBB1_3: #entry
        testl %ecx, %ecx
        jne LBB1_2      #UnifiedReturnBlock
LBB1_1: #cond_true
        call L_bar$stub
        addl $12, %esp
        ret
LBB1_2: #UnifiedReturnBlock
        addl $12, %esp
        ret

instead of:

_foo:
        subl $12, %esp
        call L_bar$stub
        movl 20(%esp), %eax
        movl 16(%esp), %ecx
        cmpl $4, %eax
        setg %al
        testl %ecx, %ecx
        setne %cl
        testb %cl, %al
        jne LBB1_2      #UnifiedReturnBlock
LBB1_1: #cond_true
        call L_bar$stub
        addl $12, %esp
        ret
LBB1_2: #UnifiedReturnBlock
        addl $12, %esp
        ret

And on ppc to:

        cmpwi cr0, r29, 5
        blt cr0, LBB1_1 ;cond_true
LBB1_3: ;entry
        cmplwi cr0, r30, 0
        bne cr0, LBB1_2 ;UnifiedReturnBlock

instead of:

        cmpwi cr7, r4, 4
        mfcr r2
        addic r4, r3, -1
        subfe r30, r4, r3
        rlwinm r29, r2, 30, 31, 31
        and r2, r29, r30
        cmplwi cr0, r2, 0
        bne cr0, LBB1_2 ;UnifiedReturnBlock


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31230 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 4 deletions

diff --git a/include/llvm/CodeGen/SelectionDAGISel.h b/include/llvm/CodeGen/SelectionDAGISel.h
index 604f6a6b9f..83269ab2d0 100644
--- a/include/llvm/CodeGen/SelectionDAGISel.h
+++ b/include/llvm/CodeGen/SelectionDAGISel.h
@@ -89,8 +89,7 @@ public:
         TrueBB(truebb), FalseBB(falsebb), ThisBB(me) {}
     // CC - the condition code to use for the case block's setcc node
     ISD::CondCode CC;
-    // CmpLHS/CmpRHS - The LHS/RHS of the comparison to emit.  If CmpRHS is
-    // null, CmpLHS is treated as a bool condition for the branch.
+    // CmpLHS/CmpRHS - The LHS/RHS of the comparison to emit.
     Value *CmpLHS, *CmpRHS;
     // TrueBB/FalseBB - the block to branch to if the setcc is true/false.
     MachineBasicBlock *TrueBB, *FalseBB;
@@ -128,8 +127,6 @@ protected:
   
 private:
   void SplitCritEdgesForPHIConstants(BasicBlock *BB);
-  SDOperand CopyValueToVirtualRegister(SelectionDAGLowering &SDL,
-                                       Value *V, unsigned Reg);
   void SelectBasicBlock(BasicBlock *BB, MachineFunction &MF,
                         FunctionLoweringInfo &FuncInfo);