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[InstSimplify] fold and/or of fcmp ord/uno when operand is known nnan
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The 'ord' and 'uno' predicates have a logic operation for NAN built into their definitions:

FCMP_ORD   =  7,  ///< 0 1 1 1    True if ordered (no nans)
FCMP_UNO   =  8,  ///< 1 0 0 0    True if unordered: isnan(X) | isnan(Y)

So we can simplify patterns like this:

(fcmp ord (known NNAN), X) && (fcmp ord X, Y) --> fcmp ord X, Y
(fcmp uno (known NNAN), X) || (fcmp uno X, Y) --> fcmp uno X, Y

It might be better to split this into (X uno 0) | (Y uno 0) as a canonicalization, but that
would be another patch.

Differential Revision: https://reviews.llvm.org/D40130 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318627 91177308-0d34-0410-b5e6-96231b3b80d8
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@rotateright
rotateright committed Nov 19, 2017
1 parent 560ee7c commit 557e920
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Showing 2 changed files with 67 additions and 59 deletions.
60 changes: 51 additions & 9 deletions lib/Analysis/InstructionSimplify.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1550,7 +1550,44 @@ static Value *simplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
return nullptr;
}

static Value *simplifyAndOrOfICmps(Value *Op0, Value *Op1, bool IsAnd) {
static Value *simplifyAndOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS, bool IsAnd) {
Value *LHS0 = LHS->getOperand(0), *LHS1 = LHS->getOperand(1);
Value *RHS0 = RHS->getOperand(0), *RHS1 = RHS->getOperand(1);
if (LHS0->getType() != RHS0->getType())
return nullptr;

FCmpInst::Predicate PredL = LHS->getPredicate(), PredR = RHS->getPredicate();
if ((PredL == FCmpInst::FCMP_ORD && PredR == FCmpInst::FCMP_ORD && IsAnd) ||
(PredL == FCmpInst::FCMP_UNO && PredR == FCmpInst::FCMP_UNO && !IsAnd)) {
// (fcmp ord NNAN, X) & (fcmp ord X, Y) --> fcmp ord X, Y
// (fcmp ord NNAN, X) & (fcmp ord Y, X) --> fcmp ord Y, X
// (fcmp ord X, NNAN) & (fcmp ord X, Y) --> fcmp ord X, Y
// (fcmp ord X, NNAN) & (fcmp ord Y, X) --> fcmp ord Y, X
// (fcmp uno NNAN, X) | (fcmp uno X, Y) --> fcmp uno X, Y
// (fcmp uno NNAN, X) | (fcmp uno Y, X) --> fcmp uno Y, X
// (fcmp uno X, NNAN) | (fcmp uno X, Y) --> fcmp uno X, Y
// (fcmp uno X, NNAN) | (fcmp uno Y, X) --> fcmp uno Y, X
if ((isKnownNeverNaN(LHS0) && (LHS1 == RHS0 || LHS1 == RHS1)) ||
(isKnownNeverNaN(LHS1) && (LHS0 == RHS0 || LHS0 == RHS1)))
return RHS;

// (fcmp ord X, Y) & (fcmp ord NNAN, X) --> fcmp ord X, Y
// (fcmp ord Y, X) & (fcmp ord NNAN, X) --> fcmp ord Y, X
// (fcmp ord X, Y) & (fcmp ord X, NNAN) --> fcmp ord X, Y
// (fcmp ord Y, X) & (fcmp ord X, NNAN) --> fcmp ord Y, X
// (fcmp uno X, Y) | (fcmp uno NNAN, X) --> fcmp uno X, Y
// (fcmp uno Y, X) | (fcmp uno NNAN, X) --> fcmp uno Y, X
// (fcmp uno X, Y) | (fcmp uno X, NNAN) --> fcmp uno X, Y
// (fcmp uno Y, X) | (fcmp uno X, NNAN) --> fcmp uno Y, X
if ((isKnownNeverNaN(RHS0) && (RHS1 == LHS0 || RHS1 == LHS1)) ||
(isKnownNeverNaN(RHS1) && (RHS0 == LHS0 || RHS0 == LHS1)))
return LHS;
}

return nullptr;
}

static Value *simplifyAndOrOfCmps(Value *Op0, Value *Op1, bool IsAnd) {
// Look through casts of the 'and' operands to find compares.
auto *Cast0 = dyn_cast<CastInst>(Op0);
auto *Cast1 = dyn_cast<CastInst>(Op1);
Expand All @@ -1560,13 +1597,18 @@ static Value *simplifyAndOrOfICmps(Value *Op0, Value *Op1, bool IsAnd) {
Op1 = Cast1->getOperand(0);
}

auto *Cmp0 = dyn_cast<ICmpInst>(Op0);
auto *Cmp1 = dyn_cast<ICmpInst>(Op1);
if (!Cmp0 || !Cmp1)
return nullptr;
Value *V = nullptr;
auto *ICmp0 = dyn_cast<ICmpInst>(Op0);
auto *ICmp1 = dyn_cast<ICmpInst>(Op1);
if (ICmp0 && ICmp1)
V = IsAnd ? simplifyAndOfICmps(ICmp0, ICmp1) :
simplifyOrOfICmps(ICmp0, ICmp1);

auto *FCmp0 = dyn_cast<FCmpInst>(Op0);
auto *FCmp1 = dyn_cast<FCmpInst>(Op1);
if (FCmp0 && FCmp1)
V = simplifyAndOrOfFCmps(FCmp0, FCmp1, IsAnd);

Value *V =
IsAnd ? simplifyAndOfICmps(Cmp0, Cmp1) : simplifyOrOfICmps(Cmp0, Cmp1);
if (!V)
return nullptr;
if (!Cast0)
Expand Down Expand Up @@ -1645,7 +1687,7 @@ static Value *SimplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
return Op1;
}

if (Value *V = simplifyAndOrOfICmps(Op0, Op1, true))
if (Value *V = simplifyAndOrOfCmps(Op0, Op1, true))
return V;

// Try some generic simplifications for associative operations.
Expand Down Expand Up @@ -1766,7 +1808,7 @@ static Value *SimplifyOrInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
match(Op0, m_c_Xor(m_Not(m_Specific(A)), m_Specific(B)))))
return Op0;

if (Value *V = simplifyAndOrOfICmps(Op0, Op1, false))
if (Value *V = simplifyAndOrOfCmps(Op0, Op1, false))
return V;

// Try some generic simplifications for associative operations.
Expand Down
66 changes: 16 additions & 50 deletions test/Transforms/InstSimplify/logic-of-fcmps.ll
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5,10 +5,8 @@

define i1 @ord1(float %x, float %y) {
; CHECK-LABEL: @ord1(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp ord float 0.000000e+00, %x
; CHECK-NEXT: [[CMP2:%.*]] = fcmp ord float %x, %y
; CHECK-NEXT: [[R:%.*]] = and i1 [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret i1 [[R]]
; CHECK-NEXT: ret i1 [[CMP2]]
;
%cmp1 = fcmp ord float 0.0, %x
%cmp2 = fcmp ord float %x, %y
Expand All @@ -18,10 +16,8 @@ define i1 @ord1(float %x, float %y) {

define i1 @ord2(double %x, double %y) {
; CHECK-LABEL: @ord2(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp ord double 4.200000e+01, %x
; CHECK-NEXT: [[CMP2:%.*]] = fcmp ord double %y, %x
; CHECK-NEXT: [[R:%.*]] = and i1 [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret i1 [[R]]
; CHECK-NEXT: ret i1 [[CMP2]]
;
%cmp1 = fcmp ord double 42.0, %x
%cmp2 = fcmp ord double %y, %x
Expand All @@ -31,10 +27,8 @@ define i1 @ord2(double %x, double %y) {

define <2 x i1> @ord3(<2 x float> %x, <2 x float> %y) {
; CHECK-LABEL: @ord3(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp ord <2 x float> %x, zeroinitializer
; CHECK-NEXT: [[CMP2:%.*]] = fcmp ord <2 x float> %x, %y
; CHECK-NEXT: [[R:%.*]] = and <2 x i1> [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret <2 x i1> [[R]]
; CHECK-NEXT: ret <2 x i1> [[CMP2]]
;
%cmp1 = fcmp ord <2 x float> %x, zeroinitializer
%cmp2 = fcmp ord <2 x float> %x, %y
Expand All @@ -44,10 +38,8 @@ define <2 x i1> @ord3(<2 x float> %x, <2 x float> %y) {

define <2 x i1> @ord4(<2 x double> %x, <2 x double> %y) {
; CHECK-LABEL: @ord4(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp ord <2 x double> %x, <double 4.200000e+01, double 4.200000e+01>
; CHECK-NEXT: [[CMP2:%.*]] = fcmp ord <2 x double> %y, %x
; CHECK-NEXT: [[R:%.*]] = and <2 x i1> [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret <2 x i1> [[R]]
; CHECK-NEXT: ret <2 x i1> [[CMP2]]
;
%cmp1 = fcmp ord <2 x double> %x, <double 42.0, double 42.0>
%cmp2 = fcmp ord <2 x double> %y, %x
Expand All @@ -57,11 +49,8 @@ define <2 x i1> @ord4(<2 x double> %x, <2 x double> %y) {

define i1 @ord5(float %x, float %y) {
; CHECK-LABEL: @ord5(
; CHECK-NEXT: [[NNAN:%.*]] = fdiv nnan float %x, %y
; CHECK-NEXT: [[CMP1:%.*]] = fcmp ord float %x, %y
; CHECK-NEXT: [[CMP2:%.*]] = fcmp ord float [[NNAN]], %x
; CHECK-NEXT: [[R:%.*]] = and i1 [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret i1 [[R]]
; CHECK-NEXT: ret i1 [[CMP1]]
;
%nnan = fdiv nnan float %x, %y
%cmp1 = fcmp ord float %x, %y
Expand All @@ -73,9 +62,7 @@ define i1 @ord5(float %x, float %y) {
define i1 @ord6(double %x, double %y) {
; CHECK-LABEL: @ord6(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp ord double %y, %x
; CHECK-NEXT: [[CMP2:%.*]] = fcmp ord double 4.200000e+01, %x
; CHECK-NEXT: [[R:%.*]] = and i1 [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret i1 [[R]]
; CHECK-NEXT: ret i1 [[CMP1]]
;
%cmp1 = fcmp ord double %y, %x
%cmp2 = fcmp ord double 42.0, %x
Expand All @@ -86,9 +73,7 @@ define i1 @ord6(double %x, double %y) {
define <2 x i1> @ord7(<2 x float> %x, <2 x float> %y) {
; CHECK-LABEL: @ord7(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp ord <2 x float> %x, %y
; CHECK-NEXT: [[CMP2:%.*]] = fcmp ord <2 x float> %x, zeroinitializer
; CHECK-NEXT: [[R:%.*]] = and <2 x i1> [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret <2 x i1> [[R]]
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%cmp1 = fcmp ord <2 x float> %x, %y
%cmp2 = fcmp ord <2 x float> %x, zeroinitializer
Expand All @@ -99,9 +84,7 @@ define <2 x i1> @ord7(<2 x float> %x, <2 x float> %y) {
define <2 x i1> @ord8(<2 x double> %x, <2 x double> %y) {
; CHECK-LABEL: @ord8(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp ord <2 x double> %y, %x
; CHECK-NEXT: [[CMP2:%.*]] = fcmp ord <2 x double> %x, <double 0.000000e+00, double 4.200000e+01>
; CHECK-NEXT: [[R:%.*]] = and <2 x i1> [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret <2 x i1> [[R]]
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%cmp1 = fcmp ord <2 x double> %y, %x
%cmp2 = fcmp ord <2 x double> %x, <double 0.0, double 42.0>
Expand All @@ -111,10 +94,8 @@ define <2 x i1> @ord8(<2 x double> %x, <2 x double> %y) {

define i1 @uno1(float %x, float %y) {
; CHECK-LABEL: @uno1(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp uno float 0.000000e+00, %x
; CHECK-NEXT: [[CMP2:%.*]] = fcmp uno float %x, %y
; CHECK-NEXT: [[R:%.*]] = or i1 [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret i1 [[R]]
; CHECK-NEXT: ret i1 [[CMP2]]
;
%cmp1 = fcmp uno float 0.0, %x
%cmp2 = fcmp uno float %x, %y
Expand All @@ -124,10 +105,8 @@ define i1 @uno1(float %x, float %y) {

define i1 @uno2(double %x, double %y) {
; CHECK-LABEL: @uno2(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp uno double 4.200000e+01, %x
; CHECK-NEXT: [[CMP2:%.*]] = fcmp uno double %y, %x
; CHECK-NEXT: [[R:%.*]] = or i1 [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret i1 [[R]]
; CHECK-NEXT: ret i1 [[CMP2]]
;
%cmp1 = fcmp uno double 42.0, %x
%cmp2 = fcmp uno double %y, %x
Expand All @@ -137,10 +116,8 @@ define i1 @uno2(double %x, double %y) {

define <2 x i1> @uno3(<2 x float> %x, <2 x float> %y) {
; CHECK-LABEL: @uno3(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp uno <2 x float> %x, zeroinitializer
; CHECK-NEXT: [[CMP2:%.*]] = fcmp uno <2 x float> %x, %y
; CHECK-NEXT: [[R:%.*]] = or <2 x i1> [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret <2 x i1> [[R]]
; CHECK-NEXT: ret <2 x i1> [[CMP2]]
;
%cmp1 = fcmp uno <2 x float> %x, zeroinitializer
%cmp2 = fcmp uno <2 x float> %x, %y
Expand All @@ -150,10 +127,8 @@ define <2 x i1> @uno3(<2 x float> %x, <2 x float> %y) {

define <2 x i1> @uno4(<2 x double> %x, <2 x double> %y) {
; CHECK-LABEL: @uno4(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp uno <2 x double> %x, <double 4.200000e+01, double 4.200000e+01>
; CHECK-NEXT: [[CMP2:%.*]] = fcmp uno <2 x double> %y, %x
; CHECK-NEXT: [[R:%.*]] = or <2 x i1> [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret <2 x i1> [[R]]
; CHECK-NEXT: ret <2 x i1> [[CMP2]]
;
%cmp1 = fcmp uno <2 x double> %x, <double 42.0, double 42.0>
%cmp2 = fcmp uno <2 x double> %y, %x
Expand All @@ -164,9 +139,7 @@ define <2 x i1> @uno4(<2 x double> %x, <2 x double> %y) {
define i1 @uno5(float %x, float %y) {
; CHECK-LABEL: @uno5(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp uno float %x, %y
; CHECK-NEXT: [[CMP2:%.*]] = fcmp uno float 0.000000e+00, %x
; CHECK-NEXT: [[R:%.*]] = or i1 [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret i1 [[R]]
; CHECK-NEXT: ret i1 [[CMP1]]
;
%cmp1 = fcmp uno float %x, %y
%cmp2 = fcmp uno float 0.0, %x
Expand All @@ -177,9 +150,7 @@ define i1 @uno5(float %x, float %y) {
define i1 @uno6(double %x, double %y) {
; CHECK-LABEL: @uno6(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp uno double %y, %x
; CHECK-NEXT: [[CMP2:%.*]] = fcmp uno double 4.200000e+01, %x
; CHECK-NEXT: [[R:%.*]] = or i1 [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret i1 [[R]]
; CHECK-NEXT: ret i1 [[CMP1]]
;
%cmp1 = fcmp uno double %y, %x
%cmp2 = fcmp uno double 42.0, %x
Expand All @@ -189,11 +160,8 @@ define i1 @uno6(double %x, double %y) {

define <2 x i1> @uno7(<2 x float> %x, <2 x float> %y) {
; CHECK-LABEL: @uno7(
; CHECK-NEXT: [[NNAN:%.*]] = fdiv nnan <2 x float> %x, %y
; CHECK-NEXT: [[CMP1:%.*]] = fcmp uno <2 x float> %x, %y
; CHECK-NEXT: [[CMP2:%.*]] = fcmp uno <2 x float> %x, [[NNAN]]
; CHECK-NEXT: [[R:%.*]] = or <2 x i1> [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret <2 x i1> [[R]]
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%nnan = fdiv nnan <2 x float> %x, %y
%cmp1 = fcmp uno <2 x float> %x, %y
Expand All @@ -205,9 +173,7 @@ define <2 x i1> @uno7(<2 x float> %x, <2 x float> %y) {
define <2 x i1> @uno8(<2 x double> %x, <2 x double> %y) {
; CHECK-LABEL: @uno8(
; CHECK-NEXT: [[CMP1:%.*]] = fcmp uno <2 x double> %y, %x
; CHECK-NEXT: [[CMP2:%.*]] = fcmp uno <2 x double> %x, <double 0x7FF0000000000000, double 4.200000e+01>
; CHECK-NEXT: [[R:%.*]] = or <2 x i1> [[CMP1]], [[CMP2]]
; CHECK-NEXT: ret <2 x i1> [[R]]
; CHECK-NEXT: ret <2 x i1> [[CMP1]]
;
%cmp1 = fcmp uno <2 x double> %y, %x
%cmp2 = fcmp uno <2 x double> %x, <double 0x7ff0000000000000, double 42.0>
Expand Down

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