[InstSimplify] Fold (ctpop(X) == N) || (X != 0) into X != 0 where N > 0

(ctpop(X) == N) || (X != 0) --> (X != 0) https://alive2.llvm.org/ce/z/udgUVV
(ctpop(X) != N) && (X == 0) --> (X == 0) https://alive2.llvm.org/ce/z/9dq-cR

Differential Revision: https://reviews.llvm.org/D122757

diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 77d600a..80fe656 100644 (file)
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -1803,6 +1803,27 @@ static Value *simplifyAndOrOfICmpsWithLimitConst(ICmpInst *Cmp0, ICmpInst *Cmp1,
   return nullptr;
 }
 
+/// Try to simplify and/or of icmp with ctpop intrinsic.
+static Value *simplifyAndOrOfICmpsWithCtpop(ICmpInst *Cmp0, ICmpInst *Cmp1,
+                                            bool IsAnd) {
+  ICmpInst::Predicate Pred0, Pred1;
+  Value *X;
+  const APInt *C;
+  if (!match(Cmp0, m_ICmp(Pred0, m_Intrinsic<Intrinsic::ctpop>(m_Value(X)),
+                          m_APInt(C))) ||
+      !match(Cmp1, m_ICmp(Pred1, m_Specific(X), m_ZeroInt())) || C->isZero())
+    return nullptr;
+
+  // (ctpop(X) == C) || (X != 0) --> X != 0 where C > 0
+  if (!IsAnd && Pred0 == ICmpInst::ICMP_EQ && Pred1 == ICmpInst::ICMP_NE)
+    return Cmp1;
+  // (ctpop(X) != C) && (X == 0) --> X == 0 where C > 0
+  if (IsAnd && Pred0 == ICmpInst::ICMP_NE && Pred1 == ICmpInst::ICMP_EQ)
+    return Cmp1;
+
+  return nullptr;
+}
+
 static Value *simplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1,
                                  const SimplifyQuery &Q) {
   if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/true, Q))
@@ -1824,6 +1845,11 @@ static Value *simplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1,
   if (Value *X = simplifyAndOrOfICmpsWithZero(Op0, Op1, true))
     return X;
 
+  if (Value *X = simplifyAndOrOfICmpsWithCtpop(Op0, Op1, true))
+    return X;
+  if (Value *X = simplifyAndOrOfICmpsWithCtpop(Op1, Op0, true))
+    return X;
+
   if (Value *X = simplifyAndOfICmpsWithAdd(Op0, Op1, Q.IIQ))
     return X;
   if (Value *X = simplifyAndOfICmpsWithAdd(Op1, Op0, Q.IIQ))
@@ -1900,6 +1926,11 @@ static Value *simplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1,
   if (Value *X = simplifyAndOrOfICmpsWithZero(Op0, Op1, false))
     return X;
 
+  if (Value *X = simplifyAndOrOfICmpsWithCtpop(Op0, Op1, false))
+    return X;
+  if (Value *X = simplifyAndOrOfICmpsWithCtpop(Op1, Op0, false))
+    return X;
+
   if (Value *X = simplifyOrOfICmpsWithAdd(Op0, Op1, Q.IIQ))
     return X;
   if (Value *X = simplifyOrOfICmpsWithAdd(Op1, Op0, Q.IIQ))

diff --git a/llvm/test/Transforms/InstSimplify/and-or-icmp-ctpop.ll b/llvm/test/Transforms/InstSimplify/and-or-icmp-ctpop.ll
index c65adb9..6de97c3 100644 (file)
--- a/llvm/test/Transforms/InstSimplify/and-or-icmp-ctpop.ll
+++ b/llvm/test/Transforms/InstSimplify/and-or-icmp-ctpop.ll
@@ -12,11 +12,8 @@ declare i32 @llvm.ctpop.i32(i32)
 
 define i1 @eq_or_non_0(i32 %x) {
 ; CHECK-LABEL: @eq_or_non_0(
-; CHECK-NEXT:    [[T0:%.*]] = tail call i32 @llvm.ctpop.i32(i32 [[X:%.*]])
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[T0]], 10
-; CHECK-NEXT:    [[NOTZERO:%.*]] = icmp ne i32 [[X]], 0
-; CHECK-NEXT:    [[R:%.*]] = or i1 [[NOTZERO]], [[CMP]]
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    [[NOTZERO:%.*]] = icmp ne i32 [[X:%.*]], 0
+; CHECK-NEXT:    ret i1 [[NOTZERO]]
 ;
   %t0 = tail call i32 @llvm.ctpop.i32(i32 %x)
   %cmp = icmp eq i32 %t0, 10
@@ -29,11 +26,8 @@ declare <2 x i32> @llvm.ctpop.v2i32(<2 x i32>)
 
 define <2 x i1> @eq_or_non_0_commute(<2 x i32> %x) {
 ; CHECK-LABEL: @eq_or_non_0_commute(
-; CHECK-NEXT:    [[T0:%.*]] = tail call <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[X:%.*]])
-; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i32> [[T0]], <i32 20, i32 20>
-; CHECK-NEXT:    [[NOTZERO:%.*]] = icmp ne <2 x i32> [[X]], zeroinitializer
-; CHECK-NEXT:    [[R:%.*]] = or <2 x i1> [[CMP]], [[NOTZERO]]
-; CHECK-NEXT:    ret <2 x i1> [[R]]
+; CHECK-NEXT:    [[NOTZERO:%.*]] = icmp ne <2 x i32> [[X:%.*]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[NOTZERO]]
 ;
   %t0 = tail call <2 x i32> @llvm.ctpop.v2i32(<2 x i32> %x)
   %cmp = icmp eq <2 x i32> %t0, <i32 20, i32 20>
@@ -68,11 +62,8 @@ define i1 @eq_or_non_0_wrong_pred1(i32 %x) {
 
 define i1 @ne_and_is_0(i32 %x) {
 ; CHECK-LABEL: @ne_and_is_0(
-; CHECK-NEXT:    [[T0:%.*]] = tail call i32 @llvm.ctpop.i32(i32 [[X:%.*]])
-; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[T0]], 10
-; CHECK-NEXT:    [[ISZERO:%.*]] = icmp eq i32 [[X]], 0
-; CHECK-NEXT:    [[R:%.*]] = and i1 [[ISZERO]], [[CMP]]
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    [[ISZERO:%.*]] = icmp eq i32 [[X:%.*]], 0
+; CHECK-NEXT:    ret i1 [[ISZERO]]
 ;
   %t0 = tail call i32 @llvm.ctpop.i32(i32 %x)
   %cmp = icmp ne i32 %t0, 10
@@ -83,11 +74,8 @@ define i1 @ne_and_is_0(i32 %x) {
 
 define <2 x i1> @ne_and_is_0_commute(<2 x i32> %x) {
 ; CHECK-LABEL: @ne_and_is_0_commute(
-; CHECK-NEXT:    [[T0:%.*]] = tail call <2 x i32> @llvm.ctpop.v2i32(<2 x i32> [[X:%.*]])
-; CHECK-NEXT:    [[CMP:%.*]] = icmp ne <2 x i32> [[T0]], <i32 20, i32 20>
-; CHECK-NEXT:    [[ISZERO:%.*]] = icmp eq <2 x i32> [[X]], zeroinitializer
-; CHECK-NEXT:    [[R:%.*]] = and <2 x i1> [[CMP]], [[ISZERO]]
-; CHECK-NEXT:    ret <2 x i1> [[R]]
+; CHECK-NEXT:    [[ISZERO:%.*]] = icmp eq <2 x i32> [[X:%.*]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[ISZERO]]
 ;
   %t0 = tail call <2 x i32> @llvm.ctpop.v2i32(<2 x i32> %x)
   %cmp = icmp ne <2 x i32> %t0, <i32 20, i32 20>