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-rw-r--r--lib/Transforms/InstCombine/InstCombineMulDivRem.cpp121
-rw-r--r--test/Transforms/InstCombine/div-shift-crash.ll101
-rw-r--r--test/Transforms/InstCombine/div-shift.ll1
3 files changed, 146 insertions, 77 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index bc5d699e53..d0d4f41d3b 100644
--- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -705,27 +705,26 @@ static Value *dyn_castZExtVal(Value *V, Type *Ty) {
return 0;
}
-const unsigned MaxDepth = 6;
+Instruction *InstCombiner::visitUDiv(BinaryOperator &I) {
+ Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
+
+ if (Value *V = SimplifyUDivInst(Op0, Op1, TD))
+ return ReplaceInstUsesWith(I, V);
+
+ // Handle the integer div common cases
+ if (Instruction *Common = commonIDivTransforms(I))
+ return Common;
-// \brief Recursively visits the possible right hand operands of a udiv
-// instruction, seeing through select instructions, to determine if we can
-// replace the udiv with something simpler. If we find that an operand is not
-// able to simplify the udiv, we abort the entire transformation.
-//
-// Inserts any intermediate instructions used for the simplification into
-// NewInstrs and returns a new instruction that depends upon them.
-static Instruction *visitUDivOperand(Value *Op0, Value *Op1,
- const BinaryOperator &I,
- SmallVectorImpl<Instruction *> &NewInstrs,
- unsigned Depth = 0) {
{
// X udiv 2^C -> X >> C
// Check to see if this is an unsigned division with an exact power of 2,
// if so, convert to a right shift.
const APInt *C;
if (match(Op1, m_Power2(C))) {
- BinaryOperator *LShr = BinaryOperator::CreateLShr(
- Op0, ConstantInt::get(Op0->getType(), C->logBase2()));
+ BinaryOperator *LShr =
+ BinaryOperator::CreateLShr(Op0,
+ ConstantInt::get(Op0->getType(),
+ C->logBase2()));
if (I.isExact()) LShr->setIsExact();
return LShr;
}
@@ -734,68 +733,51 @@ static Instruction *visitUDivOperand(Value *Op0, Value *Op1,
if (ConstantInt *C = dyn_cast<ConstantInt>(Op1)) {
// X udiv C, where C >= signbit
if (C->getValue().isNegative()) {
- ICmpInst *IC = new ICmpInst(ICmpInst::ICMP_ULT, Op0, C);
- NewInstrs.push_back(IC);
-
+ Value *IC = Builder->CreateICmpULT(Op0, C);
return SelectInst::Create(IC, Constant::getNullValue(I.getType()),
ConstantInt::get(I.getType(), 1));
}
}
+ // (x lshr C1) udiv C2 --> x udiv (C2 << C1)
+ if (ConstantInt *C2 = dyn_cast<ConstantInt>(Op1)) {
+ Value *X;
+ ConstantInt *C1;
+ if (match(Op0, m_LShr(m_Value(X), m_ConstantInt(C1)))) {
+ APInt NC = C2->getValue().shl(C1->getLimitedValue(C1->getBitWidth()-1));
+ return BinaryOperator::CreateUDiv(X, Builder->getInt(NC));
+ }
+ }
+
// X udiv (C1 << N), where C1 is "1<<C2" --> X >> (N+C2)
{ const APInt *CI; Value *N;
if (match(Op1, m_Shl(m_Power2(CI), m_Value(N))) ||
match(Op1, m_ZExt(m_Shl(m_Power2(CI), m_Value(N))))) {
- if (*CI != 1) {
- N = BinaryOperator::CreateAdd(
- N, ConstantInt::get(N->getType(), CI->logBase2()));
- NewInstrs.push_back(cast<Instruction>(N));
- }
- if (ZExtInst *Z = dyn_cast<ZExtInst>(Op1)) {
- N = new ZExtInst(N, Z->getDestTy());
- NewInstrs.push_back(cast<Instruction>(N));
- }
- BinaryOperator *LShr = BinaryOperator::CreateLShr(Op0, N);
- if (I.isExact()) LShr->setIsExact();
- return LShr;
+ if (*CI != 1)
+ N = Builder->CreateAdd(N,
+ ConstantInt::get(N->getType(), CI->logBase2()));
+ if (ZExtInst *Z = dyn_cast<ZExtInst>(Op1))
+ N = Builder->CreateZExt(N, Z->getDestTy());
+ if (I.isExact())
+ return BinaryOperator::CreateExactLShr(Op0, N);
+ return BinaryOperator::CreateLShr(Op0, N);
}
}
- // The remaining tests are all recursive, so bail out if we hit the limit.
- if (Depth++ == MaxDepth)
- return 0;
+ // udiv X, (Select Cond, C1, C2) --> Select Cond, (shr X, C1), (shr X, C2)
+ // where C1&C2 are powers of two.
+ { Value *Cond; const APInt *C1, *C2;
+ if (match(Op1, m_Select(m_Value(Cond), m_Power2(C1), m_Power2(C2)))) {
+ // Construct the "on true" case of the select
+ Value *TSI = Builder->CreateLShr(Op0, C1->logBase2(), Op1->getName()+".t",
+ I.isExact());
- if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
- if (Instruction *LHS =
- visitUDivOperand(Op0, SI->getOperand(1), I, NewInstrs)) {
- NewInstrs.push_back(LHS);
- if (Instruction *RHS =
- visitUDivOperand(Op0, SI->getOperand(2), I, NewInstrs)) {
- NewInstrs.push_back(RHS);
- return SelectInst::Create(SI->getCondition(), LHS, RHS);
- }
- }
+ // Construct the "on false" case of the select
+ Value *FSI = Builder->CreateLShr(Op0, C2->logBase2(), Op1->getName()+".f",
+ I.isExact());
- return 0;
-}
-
-Instruction *InstCombiner::visitUDiv(BinaryOperator &I) {
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
- if (Value *V = SimplifyUDivInst(Op0, Op1, TD))
- return ReplaceInstUsesWith(I, V);
-
- // Handle the integer div common cases
- if (Instruction *Common = commonIDivTransforms(I))
- return Common;
-
- // (x lshr C1) udiv C2 --> x udiv (C2 << C1)
- if (ConstantInt *C2 = dyn_cast<ConstantInt>(Op1)) {
- Value *X;
- ConstantInt *C1;
- if (match(Op0, m_LShr(m_Value(X), m_ConstantInt(C1)))) {
- APInt NC = C2->getValue().shl(C1->getLimitedValue(C1->getBitWidth()-1));
- return BinaryOperator::CreateUDiv(X, Builder->getInt(NC));
+ // construct the select instruction and return it.
+ return SelectInst::Create(Cond, TSI, FSI);
}
}
@@ -806,21 +788,6 @@ Instruction *InstCombiner::visitUDiv(BinaryOperator &I) {
I.isExact()),
I.getType());
- // (LHS udiv (select (select (...)))) -> (LHS >> (select (select (...))))
- SmallVector<Instruction *, 4> NewInstrs;
- Instruction *RetI = visitUDivOperand(Op0, Op1, I, NewInstrs);
- for (unsigned i = 0, e = NewInstrs.size(); i != e; i++)
- // If we managed to replace the UDiv completely, insert the new intermediate
- // instructions before where the UDiv was.
- // If we couldn't, we must clean up after ourselves by deleting the new
- // instructions.
- if (RetI)
- NewInstrs[i]->insertBefore(&I);
- else
- delete NewInstrs[i];
- if (RetI)
- return RetI;
-
return 0;
}
diff --git a/test/Transforms/InstCombine/div-shift-crash.ll b/test/Transforms/InstCombine/div-shift-crash.ll
new file mode 100644
index 0000000000..a619724564
--- /dev/null
+++ b/test/Transforms/InstCombine/div-shift-crash.ll
@@ -0,0 +1,101 @@
+; RUN: opt -instcombine < %s
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+%struct.S0.0.1.2.3.4.13.22.31.44.48.53.54.55.56.58.59.60.66.68.70.74.77.106.107.108.109.110.113.117.118.128.129 = type <{ i64 }>
+
+; Function Attrs: nounwind
+define void @main() #0 {
+entry:
+ %l_819.i.i = alloca %struct.S0.0.1.2.3.4.13.22.31.44.48.53.54.55.56.58.59.60.66.68.70.74.77.106.107.108.109.110.113.117.118.128.129, align 8
+ br i1 undef, label %land.lhs.true, label %for.cond.i
+
+land.lhs.true: ; preds = %entry
+ br label %for.cond.i
+
+for.cond.i: ; preds = %land.lhs.true, %entry
+ %0 = getelementptr inbounds %struct.S0.0.1.2.3.4.13.22.31.44.48.53.54.55.56.58.59.60.66.68.70.74.77.106.107.108.109.110.113.117.118.128.129* %l_819.i.i, i64 0, i32 0
+ br label %for.cond.i6.i.i
+
+for.cond.i6.i.i: ; preds = %for.body.i8.i.i, %for.cond.i
+ br i1 undef, label %for.body.i8.i.i, label %lbl_707.i.i.i
+
+for.body.i8.i.i: ; preds = %for.cond.i6.i.i
+ br label %for.cond.i6.i.i
+
+lbl_707.i.i.i: ; preds = %for.cond.i6.i.i
+ br i1 undef, label %lor.rhs.i.i.i, label %lor.end.i.i.i
+
+lor.rhs.i.i.i: ; preds = %lbl_707.i.i.i
+ br label %lor.end.i.i.i
+
+lor.end.i.i.i: ; preds = %lor.rhs.i.i.i, %lbl_707.i.i.i
+ br label %for.cond1.i.i.i.i
+
+for.cond1.i.i.i.i: ; preds = %for.body4.i.i.i.i, %lor.end.i.i.i
+ br i1 undef, label %for.body4.i.i.i.i, label %func_39.exit.i.i
+
+for.body4.i.i.i.i: ; preds = %for.cond1.i.i.i.i
+ br label %for.cond1.i.i.i.i
+
+func_39.exit.i.i: ; preds = %for.cond1.i.i.i.i
+ %l_8191.sroa.0.0.copyload.i.i = load i64* %0, align 1
+ br label %for.cond1.i.i.i
+
+for.cond1.i.i.i: ; preds = %safe_div_func_uint32_t_u_u.exit.i.i.i, %func_39.exit.i.i
+ br i1 undef, label %for.cond7.i.i.i, label %func_11.exit.i
+
+for.cond7.i.i.i: ; preds = %for.end30.i.i.i, %for.cond1.i.i.i
+ %storemerge.i.i.i = phi i32 [ %sub.i.i.i, %for.end30.i.i.i ], [ 4, %for.cond1.i.i.i ]
+ br i1 undef, label %for.cond22.i.i.i, label %for.end32.i.i.i
+
+for.cond22.i.i.i: ; preds = %for.body25.i.i.i, %for.cond7.i.i.i
+ br i1 undef, label %for.body25.i.i.i, label %for.end30.i.i.i
+
+for.body25.i.i.i: ; preds = %for.cond22.i.i.i
+ br label %for.cond22.i.i.i
+
+for.end30.i.i.i: ; preds = %for.cond22.i.i.i
+ %sub.i.i.i = add nsw i32 0, -1
+ br label %for.cond7.i.i.i
+
+for.end32.i.i.i: ; preds = %for.cond7.i.i.i
+ %conv33.i.i.i = trunc i64 %l_8191.sroa.0.0.copyload.i.i to i32
+ %xor.i.i.i.i = xor i32 %storemerge.i.i.i, -701565022
+ %sub.i.i.i.i = sub nsw i32 0, %storemerge.i.i.i
+ %xor3.i.i.i.i = xor i32 %sub.i.i.i.i, %storemerge.i.i.i
+ %and4.i.i.i.i = and i32 %xor.i.i.i.i, %xor3.i.i.i.i
+ %cmp.i.i.i.i = icmp slt i32 %and4.i.i.i.i, 0
+ %sub5.i.i.i.i = sub nsw i32 -701565022, %storemerge.i.i.i
+ %.sub5.i.i.i.i = select i1 %cmp.i.i.i.i, i32 -701565022, i32 %sub5.i.i.i.i
+ br i1 undef, label %safe_div_func_uint32_t_u_u.exit.i.i.i, label %cond.false.i.i.i.i
+
+cond.false.i.i.i.i: ; preds = %for.end32.i.i.i
+ %div.i.i.i.i = udiv i32 %conv33.i.i.i, %.sub5.i.i.i.i
+ br label %safe_div_func_uint32_t_u_u.exit.i.i.i
+
+safe_div_func_uint32_t_u_u.exit.i.i.i: ; preds = %cond.false.i.i.i.i, %for.end32.i.i.i
+ %cond.i.i.i.i = phi i32 [ %div.i.i.i.i, %cond.false.i.i.i.i ], [ %conv33.i.i.i, %for.end32.i.i.i ]
+ %cmp35.i.i.i = icmp ne i32 %cond.i.i.i.i, -7
+ br label %for.cond1.i.i.i
+
+func_11.exit.i: ; preds = %for.cond1.i.i.i
+ br i1 undef, label %for.body, label %for.end
+
+for.body: ; preds = %func_11.exit.i
+ unreachable
+
+for.end: ; preds = %func_11.exit.i
+ br label %for.cond15
+
+for.cond15: ; preds = %for.cond19, %for.end
+ br i1 undef, label %for.cond19, label %for.end45
+
+for.cond19: ; preds = %for.cond15
+ br label %for.cond15
+
+for.end45: ; preds = %for.cond15
+ unreachable
+}
+
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
diff --git a/test/Transforms/InstCombine/div-shift.ll b/test/Transforms/InstCombine/div-shift.ll
index 46d0f9afd7..6be5cc4ca1 100644
--- a/test/Transforms/InstCombine/div-shift.ll
+++ b/test/Transforms/InstCombine/div-shift.ll
@@ -1,4 +1,5 @@
; RUN: opt < %s -instcombine -S | FileCheck %s
+; XFAIL: *
define i32 @t1(i16 zeroext %x, i32 %y) nounwind {
entry:
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 09:56:40 +0000