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-rw-r--r--lib/Target/X86/X86ISelDAGToDAG.cpp128
-rw-r--r--test/CodeGen/X86/dec-eflags-lower.ll67
-rw-r--r--test/CodeGen/X86/rd-mod-wr-eflags.ll179
3 files changed, 273 insertions, 101 deletions
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index d41a240a08..03b7a1285d 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -1847,6 +1847,86 @@ static bool HasNoSignedComparisonUses(SDNode *N) {
return true;
}
+/// isLoadIncOrDecStore - Check whether or not the chain ending in StoreNode
+/// is suitable for doing the {load; increment or decrement; store} to modify
+/// transformation.
+static bool isLoadIncOrDecStore(StoreSDNode *StoreNode, unsigned Opc,
+ SDValue &StoredVal) {
+
+ // is the value stored the result of a DEC or INC?
+ if (!(Opc == X86ISD::DEC || Opc == X86ISD::INC)) return false;
+
+ // is the chain predecessor to the store a load?
+ SDValue Chain = StoreNode->getChain();
+ if (Chain->getOpcode() != ISD::LOAD) return false;
+
+ // is the size of the value one that we can handle? (i.e. 64, 32, 16, or 8)
+ LoadSDNode *LoadNode = cast<LoadSDNode>(Chain.getNode());
+ EVT LdVT = LoadNode->getMemoryVT();
+ if (LdVT != MVT::i64 && LdVT != MVT::i32 && LdVT != MVT::i16 &&
+ LdVT != MVT::i8)
+ return false;
+
+ // quick check of whether the store is simple
+ SDValue Undef = StoreNode->getOffset();
+ if (Undef->getOpcode() != ISD::UNDEF) return false;
+
+ // is the stored value result 0 of the load?
+ if (StoredVal.getResNo() != 0) return false;
+
+ // are there other uses of the loaded value than the inc or dec?
+ if (!StoredVal.getNode()->hasNUsesOfValue(1, 0)) return false;
+
+ // is there exactly one use of the load?
+ if (!LoadNode->hasNUsesOfValue(1, 0)) return false;
+
+ // are the load and store connected by the chain?
+ if (StoredVal->getOperand(0).getNode() != LoadNode) return false;
+
+ //OPC_CheckPredicate, 1, // Predicate_nontemporalstore
+ if (StoreNode->isNonTemporal())
+ return false;
+
+ // is the address of the store the same as the load?
+ SDValue Address = StoreNode->getBasePtr();
+ if (LoadNode->getBasePtr() != Address ||
+ LoadNode->getOffset() != Undef)
+ return false;
+
+ // is the load non-extending and non-indexed?
+ if (!ISD::isNormalLoad(LoadNode))
+ return false;
+
+ // is the store non-extending and non-indexed?
+ if (!ISD::isNormalStore(StoreNode))
+ return false;
+
+ // check load chain has only one use (from the store)
+ if (!Chain.hasOneUse())
+ return false;
+
+ return true;
+}
+
+/// getFusedLdStOpcode - Get the appropriate X86 opcode for an in memory
+/// increment or decrement. Opc should be X86ISD::DEC or X86ISD:INC.
+static unsigned getFusedLdStOpcode(EVT &LdVT, unsigned Opc) {
+ if (Opc == X86ISD::DEC) {
+ if (LdVT == MVT::i64) return X86::DEC64m;
+ if (LdVT == MVT::i32) return X86::DEC32m;
+ if (LdVT == MVT::i16) return X86::DEC16m;
+ if (LdVT == MVT::i8) return X86::DEC8m;
+ assert(0 && "unrecognized size for LdVT");
+ }
+ else {
+ if (LdVT == MVT::i64) return X86::INC64m;
+ if (LdVT == MVT::i32) return X86::INC32m;
+ if (LdVT == MVT::i16) return X86::INC16m;
+ if (LdVT == MVT::i8) return X86::INC8m;
+ assert(0 && "unrecognized size for LdVT");
+ }
+}
+
SDNode *X86DAGToDAGISel::Select(SDNode *Node) {
EVT NVT = Node->getValueType(0);
unsigned Opc, MOpc;
@@ -2354,9 +2434,13 @@ SDNode *X86DAGToDAGISel::Select(SDNode *Node) {
break;
}
case ISD::STORE: {
+ // Change a chain of {load; incr or dec; store} of the same value into
+ // a simple increment or decrement through memory of that value, if the
+ // uses of the modified value and its address are suitable.
// The DEC64m tablegen pattern is currently not able to match the case where
- // the EFLAGS on the original DEC are used.
- // we'll need to improve tablegen to allow flags to be transferred from a
+ // the EFLAGS on the original DEC are used. (This also applies to
+ // {INC,DEC}X{64,32,16,8}.)
+ // We'll need to improve tablegen to allow flags to be transferred from a
// node in the pattern to the result node. probably with a new keyword
// for example, we have this
// def DEC64m : RI<0xFF, MRM1m, (outs), (ins i64mem:$dst), "dec{q}\t$dst",
@@ -2366,42 +2450,16 @@ SDNode *X86DAGToDAGISel::Select(SDNode *Node) {
// def DEC64m : RI<0xFF, MRM1m, (outs), (ins i64mem:$dst), "dec{q}\t$dst",
// [(store (add (loadi64 addr:$dst), -1), addr:$dst),
// (transferrable EFLAGS)]>;
+
StoreSDNode *StoreNode = cast<StoreSDNode>(Node);
- SDValue Chain = StoreNode->getOperand(0);
SDValue StoredVal = StoreNode->getOperand(1);
- SDValue Address = StoreNode->getOperand(2);
- SDValue Undef = StoreNode->getOperand(3);
-
- if (StoreNode->getMemOperand()->getSize() != 8 ||
- Undef->getOpcode() != ISD::UNDEF ||
- Chain->getOpcode() != ISD::LOAD ||
- StoredVal->getOpcode() != X86ISD::DEC ||
- StoredVal.getResNo() != 0 ||
- !StoredVal.getNode()->hasNUsesOfValue(1, 0) ||
- !Chain.getNode()->hasNUsesOfValue(1, 0) ||
- StoredVal->getOperand(0).getNode() != Chain.getNode())
- break;
+ unsigned Opc = StoredVal->getOpcode();
- //OPC_CheckPredicate, 1, // Predicate_nontemporalstore
- if (StoreNode->isNonTemporal())
- break;
-
- LoadSDNode *LoadNode = cast<LoadSDNode>(Chain.getNode());
- if (LoadNode->getOperand(1) != Address ||
- LoadNode->getOperand(2) != Undef)
- break;
-
- if (!ISD::isNormalLoad(LoadNode))
- break;
-
- if (!ISD::isNormalStore(StoreNode))
- break;
-
- // check load chain has only one use (from the store)
- if (!Chain.hasOneUse())
- break;
+ if (!isLoadIncOrDecStore(StoreNode, Opc, StoredVal)) break;
// Merge the input chains if they are not intra-pattern references.
+ SDValue Chain = StoreNode->getOperand(0);
+ LoadSDNode *LoadNode = cast<LoadSDNode>(Chain.getNode());
SDValue InputChain = LoadNode->getOperand(0);
SDValue Base, Scale, Index, Disp, Segment;
@@ -2413,7 +2471,9 @@ SDNode *X86DAGToDAGISel::Select(SDNode *Node) {
MemOp[0] = StoreNode->getMemOperand();
MemOp[1] = LoadNode->getMemOperand();
const SDValue Ops[] = { Base, Scale, Index, Disp, Segment, InputChain };
- MachineSDNode *Result = CurDAG->getMachineNode(X86::DEC64m,
+ EVT LdVT = LoadNode->getMemoryVT();
+ unsigned newOpc = getFusedLdStOpcode(LdVT, Opc);
+ MachineSDNode *Result = CurDAG->getMachineNode(newOpc,
Node->getDebugLoc(),
MVT::i32, MVT::Other, Ops,
array_lengthof(Ops));
diff --git a/test/CodeGen/X86/dec-eflags-lower.ll b/test/CodeGen/X86/dec-eflags-lower.ll
deleted file mode 100644
index 190819f4cf..0000000000
--- a/test/CodeGen/X86/dec-eflags-lower.ll
+++ /dev/null
@@ -1,67 +0,0 @@
-; RUN: llc < %s -march=x86-64 | FileCheck %s
-
-%struct.obj = type { i64 }
-
-; CHECK: _Z7releaseP3obj
-define void @_Z7releaseP3obj(%struct.obj* nocapture %o) nounwind uwtable ssp {
-entry:
-; CHECK: decq (%{{rdi|rcx}})
-; CHECK-NEXT: je
- %refcnt = getelementptr inbounds %struct.obj* %o, i64 0, i32 0
- %0 = load i64* %refcnt, align 8, !tbaa !0
- %dec = add i64 %0, -1
- store i64 %dec, i64* %refcnt, align 8, !tbaa !0
- %tobool = icmp eq i64 %dec, 0
- br i1 %tobool, label %if.end, label %return
-
-if.end: ; preds = %entry
- %1 = bitcast %struct.obj* %o to i8*
- tail call void @free(i8* %1)
- br label %return
-
-return: ; preds = %entry, %if.end
- ret void
-}
-
-@c = common global i64 0, align 8
-@a = common global i32 0, align 4
-@.str = private unnamed_addr constant [5 x i8] c"%ld\0A\00", align 1
-@b = common global i32 0, align 4
-
-; CHECK: test
-define i32 @test() nounwind uwtable ssp {
-entry:
-; CHECK: decq
-; CHECK-NOT: decq
-%0 = load i64* @c, align 8, !tbaa !0
-%dec.i = add nsw i64 %0, -1
-store i64 %dec.i, i64* @c, align 8, !tbaa !0
-%tobool.i = icmp ne i64 %dec.i, 0
-%lor.ext.i = zext i1 %tobool.i to i32
-store i32 %lor.ext.i, i32* @a, align 4, !tbaa !3
-%call = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([5 x i8]* @.str, i64 0, i64 0), i64 %dec.i) nounwind
-ret i32 0
-}
-
-; CHECK: test2
-define i32 @test2() nounwind uwtable ssp {
-entry:
-; CHECK-NOT: decq ({{.*}})
-%0 = load i64* @c, align 8, !tbaa !0
-%dec.i = add nsw i64 %0, -1
-store i64 %dec.i, i64* @c, align 8, !tbaa !0
-%tobool.i = icmp ne i64 %0, 0
-%lor.ext.i = zext i1 %tobool.i to i32
-store i32 %lor.ext.i, i32* @a, align 4, !tbaa !3
-%call = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([5 x i8]* @.str, i64 0, i64 0), i64 %dec.i) nounwind
-ret i32 0
-}
-
-declare i32 @printf(i8* nocapture, ...) nounwind
-
-declare void @free(i8* nocapture) nounwind
-
-!0 = metadata !{metadata !"long", metadata !1}
-!1 = metadata !{metadata !"omnipotent char", metadata !2}
-!2 = metadata !{metadata !"Simple C/C++ TBAA", null}
-!3 = metadata !{metadata !"int", metadata !1}
diff --git a/test/CodeGen/X86/rd-mod-wr-eflags.ll b/test/CodeGen/X86/rd-mod-wr-eflags.ll
new file mode 100644
index 0000000000..faca3d7bac
--- /dev/null
+++ b/test/CodeGen/X86/rd-mod-wr-eflags.ll
@@ -0,0 +1,179 @@
+; RUN: llc < %s -march=x86-64 | FileCheck %s
+
+%struct.obj = type { i64 }
+
+; CHECK: _Z7releaseP3obj
+define void @_Z7releaseP3obj(%struct.obj* nocapture %o) nounwind uwtable ssp {
+entry:
+; CHECK: decq (%{{rdi|rcx}})
+; CHECK-NEXT: je
+ %refcnt = getelementptr inbounds %struct.obj* %o, i64 0, i32 0
+ %0 = load i64* %refcnt, align 8, !tbaa !0
+ %dec = add i64 %0, -1
+ store i64 %dec, i64* %refcnt, align 8, !tbaa !0
+ %tobool = icmp eq i64 %dec, 0
+ br i1 %tobool, label %if.end, label %return
+
+if.end: ; preds = %entry
+ %1 = bitcast %struct.obj* %o to i8*
+ tail call void @free(i8* %1)
+ br label %return
+
+return: ; preds = %entry, %if.end
+ ret void
+}
+
+@c = common global i64 0, align 8
+@a = common global i32 0, align 4
+@.str = private unnamed_addr constant [5 x i8] c"%ld\0A\00", align 1
+@b = common global i32 0, align 4
+
+; CHECK: test
+define i32 @test() nounwind uwtable ssp {
+entry:
+; CHECK: decq
+; CHECK-NOT: decq
+%0 = load i64* @c, align 8, !tbaa !0
+%dec.i = add nsw i64 %0, -1
+store i64 %dec.i, i64* @c, align 8, !tbaa !0
+%tobool.i = icmp ne i64 %dec.i, 0
+%lor.ext.i = zext i1 %tobool.i to i32
+store i32 %lor.ext.i, i32* @a, align 4, !tbaa !3
+%call = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([5 x i8]* @.str, i64 0, i64 0), i64 %dec.i) nounwind
+ret i32 0
+}
+
+; CHECK: test2
+define i32 @test2() nounwind uwtable ssp {
+entry:
+; CHECK-NOT: decq ({{.*}})
+%0 = load i64* @c, align 8, !tbaa !0
+%dec.i = add nsw i64 %0, -1
+store i64 %dec.i, i64* @c, align 8, !tbaa !0
+%tobool.i = icmp ne i64 %0, 0
+%lor.ext.i = zext i1 %tobool.i to i32
+store i32 %lor.ext.i, i32* @a, align 4, !tbaa !3
+%call = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([5 x i8]* @.str, i64 0, i64 0), i64 %dec.i) nounwind
+ret i32 0
+}
+
+declare i32 @printf(i8* nocapture, ...) nounwind
+
+declare void @free(i8* nocapture) nounwind
+
+!0 = metadata !{metadata !"long", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA", null}
+!3 = metadata !{metadata !"int", metadata !1}
+
+%struct.obj2 = type { i64, i32, i16, i8 }
+
+declare void @other(%struct.obj2* ) nounwind;
+
+; CHECK: example_dec
+define void @example_dec(%struct.obj2* %o) nounwind uwtable ssp {
+; 64 bit dec
+entry:
+ %s64 = getelementptr inbounds %struct.obj2* %o, i64 0, i32 0
+; CHECK-NOT: load
+ %0 = load i64* %s64, align 8
+; CHECK: decq ({{.*}})
+ %dec = add i64 %0, -1
+ store i64 %dec, i64* %s64, align 8
+ %tobool = icmp eq i64 %dec, 0
+ br i1 %tobool, label %if.end, label %return
+
+; 32 bit dec
+if.end:
+ %s32 = getelementptr inbounds %struct.obj2* %o, i64 0, i32 1
+; CHECK-NOT: load
+ %1 = load i32* %s32, align 4
+; CHECK: decl {{[0-9][0-9]*}}({{.*}})
+ %dec1 = add i32 %1, -1
+ store i32 %dec1, i32* %s32, align 4
+ %tobool2 = icmp eq i32 %dec1, 0
+ br i1 %tobool2, label %if.end1, label %return
+
+; 16 bit dec
+if.end1:
+ %s16 = getelementptr inbounds %struct.obj2* %o, i64 0, i32 2
+; CHECK-NOT: load
+ %2 = load i16* %s16, align 2
+; CHECK: decw {{[0-9][0-9]*}}({{.*}})
+ %dec2 = add i16 %2, -1
+ store i16 %dec2, i16* %s16, align 2
+ %tobool3 = icmp eq i16 %dec2, 0
+ br i1 %tobool3, label %if.end2, label %return
+
+; 8 bit dec
+if.end2:
+ %s8 = getelementptr inbounds %struct.obj2* %o, i64 0, i32 3
+; CHECK-NOT: load
+ %3 = load i8* %s8
+; CHECK: decb {{[0-9][0-9]*}}({{.*}})
+ %dec3 = add i8 %3, -1
+ store i8 %dec3, i8* %s8
+ %tobool4 = icmp eq i8 %dec3, 0
+ br i1 %tobool4, label %if.end4, label %return
+
+if.end4:
+ tail call void @other(%struct.obj2* %o) nounwind
+ br label %return
+
+return: ; preds = %if.end4, %if.end, %entry
+ ret void
+}
+
+; CHECK: example_inc
+define void @example_inc(%struct.obj2* %o) nounwind uwtable ssp {
+; 64 bit inc
+entry:
+ %s64 = getelementptr inbounds %struct.obj2* %o, i64 0, i32 0
+; CHECK-NOT: load
+ %0 = load i64* %s64, align 8
+; CHECK: incq ({{.*}})
+ %inc = add i64 %0, 1
+ store i64 %inc, i64* %s64, align 8
+ %tobool = icmp eq i64 %inc, 0
+ br i1 %tobool, label %if.end, label %return
+
+; 32 bit inc
+if.end:
+ %s32 = getelementptr inbounds %struct.obj2* %o, i64 0, i32 1
+; CHECK-NOT: load
+ %1 = load i32* %s32, align 4
+; CHECK: incl {{[0-9][0-9]*}}({{.*}})
+ %inc1 = add i32 %1, 1
+ store i32 %inc1, i32* %s32, align 4
+ %tobool2 = icmp eq i32 %inc1, 0
+ br i1 %tobool2, label %if.end1, label %return
+
+; 16 bit inc
+if.end1:
+ %s16 = getelementptr inbounds %struct.obj2* %o, i64 0, i32 2
+; CHECK-NOT: load
+ %2 = load i16* %s16, align 2
+; CHECK: incw {{[0-9][0-9]*}}({{.*}})
+ %inc2 = add i16 %2, 1
+ store i16 %inc2, i16* %s16, align 2
+ %tobool3 = icmp eq i16 %inc2, 0
+ br i1 %tobool3, label %if.end2, label %return
+
+; 8 bit inc
+if.end2:
+ %s8 = getelementptr inbounds %struct.obj2* %o, i64 0, i32 3
+; CHECK-NOT: load
+ %3 = load i8* %s8
+; CHECK: incb {{[0-9][0-9]*}}({{.*}})
+ %inc3 = add i8 %3, 1
+ store i8 %inc3, i8* %s8
+ %tobool4 = icmp eq i8 %inc3, 0
+ br i1 %tobool4, label %if.end4, label %return
+
+if.end4:
+ tail call void @other(%struct.obj2* %o) nounwind
+ br label %return
+
+return:
+ ret void
+}
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