[llvm] 22a0edd - [FPEnv] Add an option to disable strict float node mutating to an normal
Pengfei Wang via llvm-commits
llvm-commits at lists.llvm.org
Thu Nov 21 18:08:27 PST 2019
Author: Pengfei Wang
Date: 2019-11-21T18:07:11-08:00
New Revision: 22a0edd070e4a40447e0dd2699bebfd01de7a5ab
URL: https://github.com/llvm/llvm-project/commit/22a0edd070e4a40447e0dd2699bebfd01de7a5ab
DIFF: https://github.com/llvm/llvm-project/commit/22a0edd070e4a40447e0dd2699bebfd01de7a5ab.diff
LOG: [FPEnv] Add an option to disable strict float node mutating to an normal
float node
This patch add an option 'disable-strictnode-mutation' to prevent strict
node mutating to an normal node.
So we can make sure that the patch which sets strict-node as legal works
correctly.
Patch by Chen Liu(LiuChen3)
Differential Revision: https://reviews.llvm.org/D70226
Added:
Modified:
llvm/include/llvm/CodeGen/TargetLowering.h
llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
llvm/lib/CodeGen/TargetLoweringBase.cpp
llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/CodeGen/TargetLowering.h b/llvm/include/llvm/CodeGen/TargetLowering.h
index e8110983c379..56452bdbe58c 100644
--- a/llvm/include/llvm/CodeGen/TargetLowering.h
+++ b/llvm/include/llvm/CodeGen/TargetLowering.h
@@ -231,6 +231,11 @@ class TargetLoweringBase {
TargetLoweringBase &operator=(const TargetLoweringBase &) = delete;
virtual ~TargetLoweringBase() = default;
+ /// Return true if the target support strict float operation
+ bool isStrictFPEnabled() const {
+ return IsStrictFPEnabled;
+ }
+
protected:
/// Initialize all of the actions to default values.
void initActions();
@@ -2909,6 +2914,8 @@ class TargetLoweringBase {
/// details.
MachineBasicBlock *emitXRayTypedEvent(MachineInstr &MI,
MachineBasicBlock *MBB) const;
+
+ bool IsStrictFPEnabled;
};
/// This class defines information used to lower LLVM code to legal SelectionDAG
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 6602ffed020f..c3db6609f9d5 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2805,12 +2805,18 @@ bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
break;
}
case ISD::STRICT_FP_ROUND:
- // This expansion does not honor the "strict" properties anyway,
- // so prefer falling back to the non-strict operation if legal.
+ // When strict mode is enforced we can't do expansion because it
+ // does not honor the "strict" properties. Only libcall is allowed.
+ if (TLI.isStrictFPEnabled())
+ break;
+ // We might as well mutate to FP_ROUND when FP_ROUND operation is legal
+ // since this operation is more efficient than stack operation.
if (TLI.getStrictFPOperationAction(Node->getOpcode(),
Node->getValueType(0))
== TargetLowering::Legal)
break;
+ // We fall back to use stack operation when the FP_ROUND operation
+ // isn't available.
Tmp1 = EmitStackConvert(Node->getOperand(1),
Node->getValueType(0),
Node->getValueType(0), dl, Node->getOperand(0));
@@ -2825,12 +2831,18 @@ bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
Results.push_back(Tmp1);
break;
case ISD::STRICT_FP_EXTEND:
- // This expansion does not honor the "strict" properties anyway,
- // so prefer falling back to the non-strict operation if legal.
+ // When strict mode is enforced we can't do expansion because it
+ // does not honor the "strict" properties. Only libcall is allowed.
+ if (TLI.isStrictFPEnabled())
+ break;
+ // We might as well mutate to FP_EXTEND when FP_EXTEND operation is legal
+ // since this operation is more efficient than stack operation.
if (TLI.getStrictFPOperationAction(Node->getOpcode(),
Node->getValueType(0))
== TargetLowering::Legal)
break;
+ // We fall back to use stack operation when the FP_EXTEND operation
+ // isn't available.
Tmp1 = EmitStackConvert(Node->getOperand(1),
Node->getOperand(1).getValueType(),
Node->getValueType(0), dl, Node->getOperand(0));
@@ -3701,7 +3713,7 @@ bool SelectionDAGLegalize::ExpandNode(SDNode *Node) {
break;
}
- if (Results.empty() && Node->isStrictFPOpcode()) {
+ if (!TLI.isStrictFPEnabled() && Results.empty() && Node->isStrictFPOpcode()) {
// FIXME: We were asked to expand a strict floating-point operation,
// but there is currently no expansion implemented that would preserve
// the "strict" properties. For now, we just fall back to the non-strict
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
index ac4c83e8148c..2770d512c78b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
@@ -319,9 +319,9 @@ SDValue VectorLegalizer::LegalizeOp(SDValue Op) {
// best approach, except in the case where the resulting strict (scalar)
// operations would themselves use the fallback mutation to non-strict.
// In that specific case, just do the fallback on the vector op.
- if (Action == TargetLowering::Expand &&
+ if (Action == TargetLowering::Expand && !TLI.isStrictFPEnabled() &&
TLI.getStrictFPOperationAction(Node->getOpcode(),
- Node->getValueType(0))
+ Node->getValueType(0))
== TargetLowering::Legal) {
EVT EltVT = Node->getValueType(0).getVectorElementType();
if (TLI.getOperationAction(Node->getOpcode(), EltVT)
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index c6a2bfd31fee..79dbd44bb477 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1156,7 +1156,7 @@ void SelectionDAGISel::DoInstructionSelection() {
// we convert them to normal FP opcodes instead at this point. This
// will allow them to be handled by existing target-specific instruction
// selectors.
- if (Node->isStrictFPOpcode() &&
+ if (!TLI->isStrictFPEnabled() && Node->isStrictFPOpcode() &&
(TLI->getOperationAction(Node->getOpcode(), Node->getValueType(0))
== TargetLowering::Expand))
Node = CurDAG->mutateStrictFPToFP(Node);
diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index d4a7a281a27b..af7dc432eae5 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -88,6 +88,14 @@ static cl::opt<unsigned> OptsizeJumpTableDensity(
cl::desc("Minimum density for building a jump table in "
"an optsize function"));
+// FIXME: This option is only to test if the strict fp operation processed
+// correctly by preventing mutating strict fp operation to normal fp operation
+// during development. When the backend supports strict float operation, this
+// option will be meaningless.
+static cl::opt<bool> DisableStrictNodeMutation("disable-strictnode-mutation",
+ cl::desc("Don't mutate strict-float node to a legalize node"),
+ cl::init(false), cl::Hidden);
+
static bool darwinHasSinCos(const Triple &TT) {
assert(TT.isOSDarwin() && "should be called with darwin triple");
// Don't bother with 32 bit x86.
@@ -585,6 +593,7 @@ TargetLoweringBase::TargetLoweringBase(const TargetMachine &tm) : TM(tm) {
BooleanVectorContents = UndefinedBooleanContent;
SchedPreferenceInfo = Sched::ILP;
GatherAllAliasesMaxDepth = 18;
+ IsStrictFPEnabled = DisableStrictNodeMutation;
// TODO: the default will be switched to 0 in the next commit, along
// with the Target-specific changes necessary.
MaxAtomicSizeInBitsSupported = 1024;
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
index 42c18803e283..f8adca740a68 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -634,6 +634,9 @@ SystemZTargetLowering::SystemZTargetLowering(const TargetMachine &TM,
// than "STC;MVC". Handle the choice in target-specific code instead.
MaxStoresPerMemset = 0;
MaxStoresPerMemsetOptSize = 0;
+
+ // Default to having -disable-strictnode-mutation on
+ IsStrictFPEnabled = true;
}
EVT SystemZTargetLowering::getSetCCResultType(const DataLayout &DL,
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