If both parts of smul_lohi, etc. are used, don't simplify. If only one part is used, try simplify it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43888 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2007-11-08 09:25:29 +00:00
parent 01f43a4d55
commit 4471194d69
2 changed files with 160 additions and 30 deletions

View File

@ -1420,7 +1420,8 @@ SDOperand DAGCombiner::visitMULHU(SDNode *N) {
bool DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N,
unsigned LoOp, unsigned HiOp) {
// If the high half is not needed, just compute the low half.
if (!N->hasAnyUseOfValue(1) &&
bool HiExists = N->hasAnyUseOfValue(1);
if (!HiExists &&
(!AfterLegalize ||
TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0),
@ -1431,7 +1432,8 @@ bool DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N,
}
// If the low half is not needed, just compute the high half.
if (!N->hasAnyUseOfValue(0) &&
bool LoExists = N->hasAnyUseOfValue(0);
if (!LoExists &&
(!AfterLegalize ||
TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1),
@ -1441,36 +1443,35 @@ bool DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N,
return true;
}
// If the two computed results can be siplified separately, separate them.
SDOperand Lo = DAG.getNode(LoOp, N->getValueType(0),
N->op_begin(), N->getNumOperands());
SDOperand Hi = DAG.getNode(HiOp, N->getValueType(1),
N->op_begin(), N->getNumOperands());
unsigned LoExists = !Lo.use_empty();
unsigned HiExists = !Hi.use_empty();
SDOperand LoOpt = Lo;
SDOperand HiOpt = Hi;
if (!LoExists || !HiExists) {
SDOperand Pair = DAG.getNode(ISD::BUILD_PAIR, MVT::Other, Lo, Hi);
assert(Pair.use_empty() && "Pair with type MVT::Other already exists!");
LoOpt = combine(Lo.Val);
HiOpt = combine(Hi.Val);
if (!LoOpt.Val)
LoOpt = Pair.getOperand(0);
if (!HiOpt.Val)
HiOpt = Pair.getOperand(1);
DAG.DeleteNode(Pair.Val);
}
if ((LoExists || LoOpt != Lo) &&
(HiExists || HiOpt != Hi) &&
TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType()) &&
TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())) {
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), LoOpt);
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), HiOpt);
return true;
// If both halves are used, return as it is.
if (LoExists && HiExists)
return false;
// If the two computed results can be simplified separately, separate them.
bool RetVal = false;
if (LoExists) {
SDOperand Lo = DAG.getNode(LoOp, N->getValueType(0),
N->op_begin(), N->getNumOperands());
SDOperand LoOpt = combine(Lo.Val);
if (LoOpt.Val && LoOpt != Lo &&
TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())) {
RetVal = true;
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), LoOpt);
}
}
return false;
if (HiExists) {
SDOperand Hi = DAG.getNode(HiOp, N->getValueType(1),
N->op_begin(), N->getNumOperands());
SDOperand HiOpt = combine(Hi.Val);
if (HiOpt.Val && HiOpt != Hi &&
TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())) {
RetVal = true;
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), HiOpt);
}
}
return RetVal;
}
SDOperand DAGCombiner::visitSMUL_LOHI(SDNode *N) {

View File

@ -0,0 +1,129 @@
; RUN: llvm-as < %s | llc -march=x86 | not grep imul
%struct.eebb = type { %struct.eebb*, i16* }
%struct.hf = type { %struct.hf*, i16*, i8*, i32, i32, %struct.eebb*, i32, i32, i8*, i8*, i8*, i8*, i16*, i8*, i16*, %struct.ri, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [30 x i32], %struct.eebb, i32, i8* }
%struct.foo_data = type { i32, i32, i32, i32*, i32, i32, i8*, i8*, i32, i32, i32, i32, i32, i32, i32, i32, i8*, i16*, i16*, i16*, i16*, i32, i32, i32, %struct.ri*, i8*, %struct.hf* }
%struct.ri = type { %struct.ri*, i32, i8*, i16*, i32*, i32 }
define fastcc i32 @foo(i16* %eptr, i8* %ecode, %struct.foo_data* %md, i32 %ims) {
entry:
%tmp36 = load i32* null, align 4 ; <i32> [#uses=1]
%tmp37 = icmp ult i32 0, %tmp36 ; <i1> [#uses=1]
br i1 %tmp37, label %cond_next79, label %cond_true
cond_true: ; preds = %entry
ret i32 0
cond_next79: ; preds = %entry
%tmp85 = load i32* null, align 4 ; <i32> [#uses=1]
%tmp86 = icmp ult i32 0, %tmp85 ; <i1> [#uses=1]
br i1 %tmp86, label %cond_next130, label %cond_true89
cond_true89: ; preds = %cond_next79
ret i32 0
cond_next130: ; preds = %cond_next79
%tmp173 = icmp eq i32 0, 0 ; <i1> [#uses=1]
br i1 %tmp173, label %cond_next201, label %cond_true176
cond_true176: ; preds = %cond_next130
ret i32 0
cond_next201: ; preds = %cond_next130
switch i32 0, label %bb19955 [
i32 0, label %bb1266
i32 1, label %bb5018
i32 2, label %bb5075
i32 3, label %cond_true5534
i32 4, label %cond_true5534
i32 5, label %bb6039
i32 6, label %bb6181
i32 7, label %bb6323
i32 8, label %bb6463
i32 9, label %bb6605
i32 10, label %bb6746
i32 11, label %cond_next5871
i32 16, label %bb5452
i32 17, label %bb5395
i32 19, label %bb4883
i32 20, label %bb5136
i32 23, label %bb12899
i32 64, label %bb2162
i32 69, label %bb1447
i32 70, label %bb1737
i32 71, label %bb1447
i32 72, label %bb1737
i32 73, label %cond_true1984
i32 75, label %bb740
i32 80, label %bb552
]
bb552: ; preds = %cond_next201
ret i32 0
bb740: ; preds = %cond_next201
ret i32 0
bb1266: ; preds = %cond_next201
ret i32 0
bb1447: ; preds = %cond_next201, %cond_next201
ret i32 0
bb1737: ; preds = %cond_next201, %cond_next201
ret i32 0
cond_true1984: ; preds = %cond_next201
ret i32 0
bb2162: ; preds = %cond_next201
ret i32 0
bb4883: ; preds = %cond_next201
ret i32 0
bb5018: ; preds = %cond_next201
ret i32 0
bb5075: ; preds = %cond_next201
ret i32 0
bb5136: ; preds = %cond_next201
ret i32 0
bb5395: ; preds = %cond_next201
ret i32 0
bb5452: ; preds = %cond_next201
ret i32 0
cond_true5534: ; preds = %cond_next201, %cond_next201
ret i32 0
cond_next5871: ; preds = %cond_next201
ret i32 0
bb6039: ; preds = %cond_next201
ret i32 0
bb6181: ; preds = %cond_next201
ret i32 0
bb6323: ; preds = %cond_next201
ret i32 0
bb6463: ; preds = %cond_next201
ret i32 0
bb6605: ; preds = %cond_next201
ret i32 0
bb6746: ; preds = %cond_next201
ret i32 0
bb12899: ; preds = %cond_next201
ret i32 0
bb19955: ; preds = %cond_next201
ret i32 0
}