diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h
--- a/llvm/include/llvm/CodeGen/SelectionDAG.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAG.h
@@ -1077,7 +1077,8 @@
/// Try to simplify a floating-point binary operation into 1 of its operands
/// or a constant.
- SDValue simplifyFPBinop(unsigned Opcode, SDValue X, SDValue Y);
+ SDValue simplifyFPBinop(unsigned Opcode, SDValue X, SDValue Y,
+ SDNodeFlags Flags);
/// VAArg produces a result and token chain, and takes a pointer
/// and a source value as input.
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -12220,6 +12220,9 @@
const TargetOptions &Options = DAG.getTarget().Options;
const SDNodeFlags Flags = N->getFlags();
+ if (SDValue R = DAG.simplifyFPBinop(N->getOpcode(), N0, N1, Flags))
+ return R;
+
// fold vector ops
if (VT.isVector())
if (SDValue FoldedVOp = SimplifyVBinOp(N))
@@ -12401,6 +12404,9 @@
const TargetOptions &Options = DAG.getTarget().Options;
const SDNodeFlags Flags = N->getFlags();
+ if (SDValue R = DAG.simplifyFPBinop(N->getOpcode(), N0, N1, Flags))
+ return R;
+
// fold vector ops
if (VT.isVector())
if (SDValue FoldedVOp = SimplifyVBinOp(N))
@@ -12499,6 +12505,9 @@
const TargetOptions &Options = DAG.getTarget().Options;
const SDNodeFlags Flags = N->getFlags();
+ if (SDValue R = DAG.simplifyFPBinop(N->getOpcode(), N0, N1, Flags))
+ return R;
+
// fold vector ops
if (VT.isVector()) {
// This just handles C1 * C2 for vectors. Other vector folds are below.
@@ -12831,6 +12840,9 @@
const TargetOptions &Options = DAG.getTarget().Options;
SDNodeFlags Flags = N->getFlags();
+ if (SDValue R = DAG.simplifyFPBinop(N->getOpcode(), N0, N1, Flags))
+ return R;
+
// fold vector ops
if (VT.isVector())
if (SDValue FoldedVOp = SimplifyVBinOp(N))
@@ -12931,6 +12943,10 @@
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
EVT VT = N->getValueType(0);
+ SDNodeFlags Flags = N->getFlags();
+
+ if (SDValue R = DAG.simplifyFPBinop(N->getOpcode(), N0, N1, Flags))
+ return R;
// fold (frem c1, c2) -> fmod(c1,c2)
if (N0CFP && N1CFP)
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5229,7 +5229,7 @@
assert(VT.isFloatingPoint() && "This operator only applies to FP types!");
assert(N1.getValueType() == N2.getValueType() &&
N1.getValueType() == VT && "Binary operator types must match!");
- if (SDValue V = simplifyFPBinop(Opcode, N1, N2))
+ if (SDValue V = simplifyFPBinop(Opcode, N1, N2, Flags))
return V;
break;
case ISD::FCOPYSIGN: // N1 and result must match. N1/N2 need not match.
@@ -7301,9 +7301,24 @@
return SDValue();
}
-// TODO: Use fast-math-flags to enable more simplifications.
-SDValue SelectionDAG::simplifyFPBinop(unsigned Opcode, SDValue X, SDValue Y) {
+SDValue SelectionDAG::simplifyFPBinop(unsigned Opcode, SDValue X, SDValue Y,
+ SDNodeFlags Flags) {
+ // If this operation has 'nnan' or 'ninf' and at least 1 disallowed operand
+ // (an undef operand can be chosen to be Nan/Inf), then the result of this
+ // operation is poison. That result can be relaxed to undef.
+ ConstantFPSDNode *XC = isConstOrConstSplatFP(X, /* AllowUndefs */ true);
ConstantFPSDNode *YC = isConstOrConstSplatFP(Y, /* AllowUndefs */ true);
+ bool HasNan = (XC && XC->getValueAPF().isNaN()) ||
+ (YC && YC->getValueAPF().isNaN());
+ bool HasInf = (XC && XC->getValueAPF().isInfinity()) ||
+ (YC && YC->getValueAPF().isInfinity());
+
+ if (Flags.hasNoNaNs() && (HasNan || X.isUndef() || Y.isUndef()))
+ return getUNDEF(X.getValueType());
+
+ if (Flags.hasNoInfs() && (HasInf || X.isUndef() || Y.isUndef()))
+ return getUNDEF(X.getValueType());
+
if (!YC)
return SDValue();
diff --git a/llvm/test/CodeGen/AArch64/fp-const-fold.ll b/llvm/test/CodeGen/AArch64/fp-const-fold.ll
--- a/llvm/test/CodeGen/AArch64/fp-const-fold.ll
+++ b/llvm/test/CodeGen/AArch64/fp-const-fold.ll
@@ -76,9 +76,6 @@
define double @fdiv_nnan_nan_op0(double %x) {
; CHECK-LABEL: fdiv_nnan_nan_op0:
; CHECK: // %bb.0:
-; CHECK-NEXT: mov x8, #-2251799813685248
-; CHECK-NEXT: fmov d1, x8
-; CHECK-NEXT: fdiv d0, d1, d0
; CHECK-NEXT: ret
%r = fdiv nnan double 0xfff8000000000000, %x
ret double %r
@@ -87,14 +84,14 @@
define double @fmul_nnan_nan_op1(double %x) {
; CHECK-LABEL: fmul_nnan_nan_op1:
; CHECK: // %bb.0:
-; CHECK-NEXT: mov x8, #9221120237041090560
-; CHECK-NEXT: fmov d1, x8
-; CHECK-NEXT: fmul d0, d0, d1
; CHECK-NEXT: ret
%r = fmul nnan double %x, 0x7ff8000000000000
ret double %r
}
+; Negative test - nan is ok.
+; TODO: Should simplify to nan.
+
define double @fdiv_ninf_nan_op0(double %x) {
; CHECK-LABEL: fdiv_ninf_nan_op0:
; CHECK: // %bb.0:
@@ -106,6 +103,9 @@
ret double %r
}
+; Negative test - nan is ok.
+; TODO: Should simplify to nan.
+
define double @fadd_ninf_nan_op1(double %x) {
; CHECK-LABEL: fadd_ninf_nan_op1:
; CHECK: // %bb.0:
@@ -120,9 +120,6 @@
define double @fdiv_ninf_inf_op0(double %x) {
; CHECK-LABEL: fdiv_ninf_inf_op0:
; CHECK: // %bb.0:
-; CHECK-NEXT: mov x8, #9218868437227405312
-; CHECK-NEXT: fmov d1, x8
-; CHECK-NEXT: fdiv d0, d1, d0
; CHECK-NEXT: ret
%r = fdiv ninf double 0x7ff0000000000000, %x
ret double %r
@@ -131,14 +128,14 @@
define double @fadd_ninf_inf_op1(double %x) {
; CHECK-LABEL: fadd_ninf_inf_op1:
; CHECK: // %bb.0:
-; CHECK-NEXT: mov x8, #-4503599627370496
-; CHECK-NEXT: fmov d1, x8
-; CHECK-NEXT: fadd d0, d0, d1
; CHECK-NEXT: ret
%r = fadd ninf double %x, 0xfff0000000000000
ret double %r
}
+; Negative test - inf is ok.
+; TODO: Should simplify to inf.
+
define double @fsub_nnan_inf_op0(double %x) {
; CHECK-LABEL: fsub_nnan_inf_op0:
; CHECK: // %bb.0:
@@ -150,6 +147,9 @@
ret double %r
}
+; Negative test - inf is ok.
+; TODO: Should simplify to -inf.
+
define double @fmul_nnan_inf_op1(double %x) {
; CHECK-LABEL: fmul_nnan_inf_op1:
; CHECK: // %bb.0:
@@ -161,6 +161,8 @@
ret double %r
}
+; TODO: Should simplify to undef
+
define double @fdiv_nnan_undef_op0(double %x) {
; CHECK-LABEL: fdiv_nnan_undef_op0:
; CHECK: // %bb.0:
@@ -171,6 +173,8 @@
ret double %r
}
+; TODO: Should simplify to undef
+
define double @fdiv_nnan_undef_op1(double %x) {
; CHECK-LABEL: fdiv_nnan_undef_op1:
; CHECK: // %bb.0:
@@ -181,6 +185,8 @@
ret double %r
}
+; TODO: Should simplify to undef
+
define double @fdiv_ninf_undef_op0(double %x) {
; CHECK-LABEL: fdiv_ninf_undef_op0:
; CHECK: // %bb.0:
@@ -191,6 +197,8 @@
ret double %r
}
+; TODO: Should simplify to undef
+
define double @fdiv_ninf_undef_op1(double %x) {
; CHECK-LABEL: fdiv_ninf_undef_op1:
; CHECK: // %bb.0: