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| author | Chris Lattner <sabre@nondot.org> | 2005-04-12 00:28:49 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2005-04-12 00:28:49 +0000 |
| commit | 87bd69884a2f658b7809a326722065532721b805 (patch) | |
| tree | 3ff2b1606cfe85581075fb920b1e802bb1ef7af2 /llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | |
| parent | 79a3bea4ca1e0649074230ad55a954711f2e62b9 (diff) | |
| download | bcm5719-llvm-87bd69884a2f658b7809a326722065532721b805.tar.gz bcm5719-llvm-87bd69884a2f658b7809a326722065532721b805.zip | |
canonicalize x <u 1 -> x == 0. On this testcase:
unsigned long long g;
unsigned long foo (unsigned long a) {
return (a >= g) ? 1 : 0;
}
It changes the ppc code from:
_foo:
.LBB_foo_0: ; entry
mflr r11
stw r11, 8(r1)
bl "L00000$pb"
"L00000$pb":
mflr r2
addis r2, r2, ha16(L_g$non_lazy_ptr-"L00000$pb")
lwz r2, lo16(L_g$non_lazy_ptr-"L00000$pb")(r2)
lwz r4, 0(r2)
lwz r2, 4(r2)
cmplw cr0, r3, r2
li r2, 1
li r3, 0
bge .LBB_foo_2 ; entry
.LBB_foo_1: ; entry
or r2, r3, r3
.LBB_foo_2: ; entry
cmplwi cr0, r4, 1
li r3, 1
li r5, 0
blt .LBB_foo_4 ; entry
.LBB_foo_3: ; entry
or r3, r5, r5
.LBB_foo_4: ; entry
cmpwi cr0, r4, 0
beq .LBB_foo_6 ; entry
.LBB_foo_5: ; entry
or r2, r3, r3
.LBB_foo_6: ; entry
rlwinm r3, r2, 0, 31, 31
lwz r11, 8(r1)
mtlr r11
blr
to:
_foo:
.LBB_foo_0: ; entry
mflr r11
stw r11, 8(r1)
bl "L00000$pb"
"L00000$pb":
mflr r2
addis r2, r2, ha16(L_g$non_lazy_ptr-"L00000$pb")
lwz r2, lo16(L_g$non_lazy_ptr-"L00000$pb")(r2)
lwz r4, 0(r2)
lwz r2, 4(r2)
cmplw cr0, r3, r2
li r2, 1
li r3, 0
bge .LBB_foo_2 ; entry
.LBB_foo_1: ; entry
or r2, r3, r3
.LBB_foo_2: ; entry
cntlzw r3, r4
srwi r3, r3, 5
cmpwi cr0, r4, 0
beq .LBB_foo_4 ; entry
.LBB_foo_3: ; entry
or r2, r3, r3
.LBB_foo_4: ; entry
rlwinm r3, r2, 0, 31, 31
lwz r11, 8(r1)
mtlr r11
blr
llvm-svn: 21241
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 513bab2f538..0243ebf5df3 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -429,6 +429,15 @@ SDOperand SelectionDAG::getSetCC(ISD::CondCode Cond, MVT::ValueType VT, N2 = getConstant(C2, N2.getValueType()); N2C = cast<ConstantSDNode>(N2.Val); } + + // If we have setult X, 1, turn it into seteq X, 0 + if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C2 == MinVal+1) + return getSetCC(ISD::SETEQ, VT, N1, + getConstant(MinVal, N1.getValueType())); + // If we have setult X, 1, turn it into seteq X, 0 + else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C2 == MaxVal-1) + return getSetCC(ISD::SETEQ, VT, N1, + getConstant(MaxVal, N1.getValueType())); // If we have "setcc X, C1", check to see if we can shrink the immediate // by changing cc. |
