Add some folds for == and != comparisons. This allows us to

codegen this loop in stepanov:

no_exit.i:              ; preds = %entry, %no_exit.i, %then.i, %_Z5checkd.exit
        %i.0.0 = phi int [ 0, %entry ], [ %i.0.0, %no_exit.i ], [ %inc.0, %_Z5checkd.exit ], [ %inc.012, %then.i ]              ; <int> [#uses=3]
        %indvar = phi uint [ %indvar.next, %no_exit.i ], [ 0, %entry ], [ 0, %then.i ], [ 0, %_Z5checkd.exit ]          ; <uint> [#uses=3]
        %result_addr.i.0 = phi double [ %tmp.4.i.i, %no_exit.i ], [ 0.000000e+00, %entry ], [ 0.000000e+00, %then.i ], [ 0.000000e+00, %_Z5checkd.exit ]          ; <double> [#uses=1]
        %first_addr.0.i.2.rec = cast uint %indvar to int                ; <int> [#uses=1]
        %first_addr.0.i.2 = getelementptr [2000 x double]* %data, int 0, uint %indvar           ; <double*> [#uses=1]
        %inc.i.rec = add int %first_addr.0.i.2.rec, 1           ; <int> [#uses=1]
        %inc.i = getelementptr [2000 x double]* %data, int 0, int %inc.i.rec            ; <double*> [#uses=1]
        %tmp.3.i.i = load double* %first_addr.0.i.2             ; <double> [#uses=1]
        %tmp.4.i.i = add double %result_addr.i.0, %tmp.3.i.i            ; <double> [#uses=2]
        %tmp.2.i = seteq double* %inc.i, getelementptr ([2000 x double]* %data, int 0, int 2000)                ; <bool> [#uses=1]
        %indvar.next = add uint %indvar, 1              ; <uint> [#uses=1]
        br bool %tmp.2.i, label %_Z10accumulateIPddET0_T_S2_S1_.exit, label %no_exit.i

To this:

.LBB_Z4testIPddEvT_S1_T0__1:    # no_exit.i
        fldl data(,%eax,8)
        fldl 16(%esp)
        faddp %st(1)
        fstpl 16(%esp)
        incl %eax
        movl %eax, %ecx
        shll $3, %ecx
        cmpl $16000, %ecx
        #FP_REG_KILL
        jne .LBB_Z4testIPddEvT_S1_T0__1 # no_exit.i

instead of this:

.LBB_Z4testIPddEvT_S1_T0__1:    # no_exit.i
        fldl data(,%eax,8)
        fldl 16(%esp)
        faddp %st(1)
        fstpl 16(%esp)
        incl %eax
        leal data(,%eax,8), %ecx
        leal data+16000, %edx
        cmpl %edx, %ecx
        #FP_REG_KILL
        jne .LBB_Z4testIPddEvT_S1_T0__1 # no_exit.i


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19425 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2005-01-09 20:52:51 +00:00
parent 1d7b5de7ee
commit 5cdcc58d51

View File

@ -22,6 +22,47 @@
#include <algorithm>
using namespace llvm;
static bool isCommutativeBinOp(unsigned Opcode) {
switch (Opcode) {
case ISD::ADD:
case ISD::MUL:
case ISD::AND:
case ISD::OR:
case ISD::XOR: return true;
default: return false; // FIXME: Need commutative info for user ops!
}
}
static bool isAssociativeBinOp(unsigned Opcode) {
switch (Opcode) {
case ISD::ADD:
case ISD::MUL:
case ISD::AND:
case ISD::OR:
case ISD::XOR: return true;
default: return false; // FIXME: Need associative info for user ops!
}
}
static unsigned ExactLog2(uint64_t Val) {
unsigned Count = 0;
while (Val != 1) {
Val >>= 1;
++Count;
}
return Count;
}
// isInvertibleForFree - Return true if there is no cost to emitting the logical
// inverse of this node.
static bool isInvertibleForFree(SDOperand N) {
if (isa<ConstantSDNode>(N.Val)) return true;
if (isa<SetCCSDNode>(N.Val) && N.Val->hasOneUse())
return true;
return false;
}
/// getSetCCSwappedOperands - Return the operation corresponding to (Y op X)
/// when given the operation for (X op Y).
ISD::CondCode ISD::getSetCCSwappedOperands(ISD::CondCode Operation) {
@ -357,6 +398,23 @@ SDOperand SelectionDAG::getSetCC(ISD::CondCode Cond, SDOperand N1,
Cond = UOF == 0 ? ISD::SETUO : ISD::SETO;
}
// Simplify (X+Y) == (X+Z) --> Y == Z
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
N1.getOpcode() == N2.getOpcode() && MVT::isInteger(N1.getValueType()))
if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB) {
if (N1.getOperand(0) == N2.getOperand(0))
return getSetCC(Cond, N1.getOperand(1), N2.getOperand(1));
if (N1.getOperand(1) == N2.getOperand(1))
return getSetCC(Cond, N1.getOperand(0), N2.getOperand(0));
if (isCommutativeBinOp(N1.getOpcode())) {
// If X op Y == Y op X, try other combinations.
if (N1.getOperand(0) == N2.getOperand(1))
return getSetCC(Cond, N1.getOperand(1), N2.getOperand(0));
if (N1.getOperand(1) == N2.getOperand(0))
return getSetCC(Cond, N1.getOperand(1), N2.getOperand(1));
}
}
SetCCSDNode *&N = SetCCs[std::make_pair(std::make_pair(N1, N2), Cond)];
if (N) return SDOperand(N, 0);
@ -449,47 +507,6 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
return SDOperand(N, 0);
}
static bool isCommutativeBinOp(unsigned Opcode) {
switch (Opcode) {
case ISD::ADD:
case ISD::MUL:
case ISD::AND:
case ISD::OR:
case ISD::XOR: return true;
default: return false; // FIXME: Need commutative info for user ops!
}
}
static bool isAssociativeBinOp(unsigned Opcode) {
switch (Opcode) {
case ISD::ADD:
case ISD::MUL:
case ISD::AND:
case ISD::OR:
case ISD::XOR: return true;
default: return false; // FIXME: Need associative info for user ops!
}
}
static unsigned ExactLog2(uint64_t Val) {
unsigned Count = 0;
while (Val != 1) {
Val >>= 1;
++Count;
}
return Count;
}
// isInvertibleForFree - Return true if there is no cost to emitting the logical
// inverse of this node.
static bool isInvertibleForFree(SDOperand N) {
if (isa<ConstantSDNode>(N.Val)) return true;
if (isa<SetCCSDNode>(N.Val) && N.Val->hasOneUse())
return true;
return false;
}
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2) {
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);