[llvm] r275483 - [GVN] Fold constant expression in GVN.
Ekaterina Romanova via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 14 15:02:25 PDT 2016
Author: kromanova
Date: Thu Jul 14 17:02:25 2016
New Revision: 275483
URL: http://llvm.org/viewvc/llvm-project?rev=275483&view=rev
Log:
[GVN] Fold constant expression in GVN.
Fix for PR 28418.
opt never finishes compiling a test when -gvn option is passed.
The problem is caused by the fact that GVN fails to fold a constant expression.
Differential Revision: https://reviews.llvm.org/D22185
Added:
llvm/trunk/test/Transforms/GVN/fold-const-expr.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/GVN.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/GVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVN.cpp?rev=275483&r1=275482&r2=275483&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVN.cpp Thu Jul 14 17:02:25 2016
@@ -725,6 +725,9 @@ static Value *CoerceAvailableValueToLoad
assert(CanCoerceMustAliasedValueToLoad(StoredVal, LoadedTy, DL) &&
"precondition violation - materialization can't fail");
+ if (auto *CExpr = dyn_cast<ConstantExpr>(StoredVal))
+ StoredVal = ConstantFoldConstantExpression(CExpr, DL);
+
// If this is already the right type, just return it.
Type *StoredValTy = StoredVal->getType();
@@ -735,25 +738,29 @@ static Value *CoerceAvailableValueToLoad
if (StoredValSize == LoadedValSize) {
// Pointer to Pointer -> use bitcast.
if (StoredValTy->getScalarType()->isPointerTy() &&
- LoadedTy->getScalarType()->isPointerTy())
- return IRB.CreateBitCast(StoredVal, LoadedTy);
-
- // Convert source pointers to integers, which can be bitcast.
- if (StoredValTy->getScalarType()->isPointerTy()) {
- StoredValTy = DL.getIntPtrType(StoredValTy);
- StoredVal = IRB.CreatePtrToInt(StoredVal, StoredValTy);
+ LoadedTy->getScalarType()->isPointerTy()) {
+ StoredVal = IRB.CreateBitCast(StoredVal, LoadedTy);
+ } else {
+ // Convert source pointers to integers, which can be bitcast.
+ if (StoredValTy->getScalarType()->isPointerTy()) {
+ StoredValTy = DL.getIntPtrType(StoredValTy);
+ StoredVal = IRB.CreatePtrToInt(StoredVal, StoredValTy);
+ }
+
+ Type *TypeToCastTo = LoadedTy;
+ if (TypeToCastTo->getScalarType()->isPointerTy())
+ TypeToCastTo = DL.getIntPtrType(TypeToCastTo);
+
+ if (StoredValTy != TypeToCastTo)
+ StoredVal = IRB.CreateBitCast(StoredVal, TypeToCastTo);
+
+ // Cast to pointer if the load needs a pointer type.
+ if (LoadedTy->getScalarType()->isPointerTy())
+ StoredVal = IRB.CreateIntToPtr(StoredVal, LoadedTy);
}
- Type *TypeToCastTo = LoadedTy;
- if (TypeToCastTo->getScalarType()->isPointerTy())
- TypeToCastTo = DL.getIntPtrType(TypeToCastTo);
-
- if (StoredValTy != TypeToCastTo)
- StoredVal = IRB.CreateBitCast(StoredVal, TypeToCastTo);
-
- // Cast to pointer if the load needs a pointer type.
- if (LoadedTy->getScalarType()->isPointerTy())
- StoredVal = IRB.CreateIntToPtr(StoredVal, LoadedTy);
+ if (auto *CExpr = dyn_cast<ConstantExpr>(StoredVal))
+ StoredVal = ConstantFoldConstantExpression(CExpr, DL);
return StoredVal;
}
@@ -788,15 +795,19 @@ static Value *CoerceAvailableValueToLoad
Type *NewIntTy = IntegerType::get(StoredValTy->getContext(), LoadedValSize);
StoredVal = IRB.CreateTrunc(StoredVal, NewIntTy, "trunc");
- if (LoadedTy == NewIntTy)
- return StoredVal;
+ if (LoadedTy != NewIntTy) {
+ // If the result is a pointer, inttoptr.
+ if (LoadedTy->getScalarType()->isPointerTy())
+ StoredVal = IRB.CreateIntToPtr(StoredVal, LoadedTy, "inttoptr");
+ else
+ // Otherwise, bitcast.
+ StoredVal = IRB.CreateBitCast(StoredVal, LoadedTy, "bitcast");
+ }
- // If the result is a pointer, inttoptr.
- if (LoadedTy->getScalarType()->isPointerTy())
- return IRB.CreateIntToPtr(StoredVal, LoadedTy, "inttoptr");
+ if (auto *CExpr = dyn_cast<ConstantExpr>(StoredVal))
+ StoredVal = ConstantFoldConstantExpression(CExpr, DL);
- // Otherwise, bitcast.
- return IRB.CreateBitCast(StoredVal, LoadedTy, "bitcast");
+ return StoredVal;
}
/// This function is called when we have a
Added: llvm/trunk/test/Transforms/GVN/fold-const-expr.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/GVN/fold-const-expr.ll?rev=275483&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/GVN/fold-const-expr.ll (added)
+++ llvm/trunk/test/Transforms/GVN/fold-const-expr.ll Thu Jul 14 17:02:25 2016
@@ -0,0 +1,99 @@
+; GVN failed to do constant expression folding and expanded
+; them unfolded in many places, producing exponentially large const
+; expressions. As a result, the compilation never fisished.
+; This test checks that we are folding constant expression
+; PR 28418
+; RUN: opt -gvn -S < %s | FileCheck %s
+
+%2 = type { i32, i32, i32, i32, i32 }
+define i32 @_Z16vector3util_mainv(i32 %x, i32 %y) {
+ %tmp1 = alloca %2, align 4
+ %tmp114 = getelementptr inbounds %2, %2* %tmp1, i64 0, i32 1
+ %tmp115 = bitcast i32* %tmp114 to <4 x i32>*
+ store <4 x i32> <i32 234567891, i32 345678912, i32 456789123, i32 0>, <4 x i32>* %tmp115, align 4
+ %tmp1683 = getelementptr inbounds %2, %2* %tmp1, i64 0, i32 1
+ %tmp1688 = load i32, i32* %tmp1683, align 4
+ %tmp1693 = shl i32 %tmp1688, 5
+ %tmp1694 = xor i32 %tmp1693, %tmp1688
+ %tmp1695 = lshr i32 %tmp1694, 7
+ %tmp1696 = xor i32 %tmp1695, %tmp1694
+ %tmp1697 = shl i32 %tmp1696, 22
+ %tmp1698 = xor i32 %tmp1697, %tmp1696
+ %tmp1707 = shl i32 %tmp1698, 5
+ %tmp1708 = xor i32 %tmp1707, %tmp1698
+ %tmp1709 = lshr i32 %tmp1708, 7
+ %tmp1710 = xor i32 %tmp1709, %tmp1708
+ %tmp1711 = shl i32 %tmp1710, 22
+ %tmp1712 = xor i32 %tmp1711, %tmp1710
+ %tmp1721 = shl i32 %tmp1712, 5
+ %tmp1722 = xor i32 %tmp1721, %tmp1712
+ %tmp1723 = lshr i32 %tmp1722, 7
+ %tmp1724 = xor i32 %tmp1723, %tmp1722
+ %tmp1725 = shl i32 %tmp1724, 22
+ %tmp1726 = xor i32 %tmp1725, %tmp1724
+ %tmp1735 = shl i32 %tmp1726, 5
+ %tmp1736 = xor i32 %tmp1735, %tmp1726
+ %tmp1737 = lshr i32 %tmp1736, 7
+ %tmp1738 = xor i32 %tmp1737, %tmp1736
+ %tmp1739 = shl i32 %tmp1738, 22
+ %tmp1740 = xor i32 %tmp1739, %tmp1738
+ store i32 %tmp1740, i32* %tmp1683, align 4
+; CHECK: store i32 310393545, i32* %tmp114, align 4
+ %tmp1756 = getelementptr inbounds %2, %2* %tmp1, i64 0, i32 1
+ %tmp1761 = load i32, i32* %tmp1756, align 4
+ %tmp1766 = shl i32 %tmp1761, 5
+ %tmp1767 = xor i32 %tmp1766, %tmp1761
+ %tmp1768 = lshr i32 %tmp1767, 7
+ %tmp1769 = xor i32 %tmp1768, %tmp1767
+ %tmp1770 = shl i32 %tmp1769, 22
+ %tmp1771 = xor i32 %tmp1770, %tmp1769
+ %tmp1780 = shl i32 %tmp1771, 5
+ %tmp1781 = xor i32 %tmp1780, %tmp1771
+ %tmp1782 = lshr i32 %tmp1781, 7
+ %tmp1783 = xor i32 %tmp1782, %tmp1781
+ %tmp1784 = shl i32 %tmp1783, 22
+ %tmp1785 = xor i32 %tmp1784, %tmp1783
+ %tmp1794 = shl i32 %tmp1785, 5
+ %tmp1795 = xor i32 %tmp1794, %tmp1785
+ %tmp1796 = lshr i32 %tmp1795, 7
+ %tmp1797 = xor i32 %tmp1796, %tmp1795
+ %tmp1798 = shl i32 %tmp1797, 22
+ %tmp1799 = xor i32 %tmp1798, %tmp1797
+ %tmp1808 = shl i32 %tmp1799, 5
+ %tmp1809 = xor i32 %tmp1808, %tmp1799
+ %tmp1810 = lshr i32 %tmp1809, 7
+ %tmp1811 = xor i32 %tmp1810, %tmp1809
+ %tmp1812 = shl i32 %tmp1811, 22
+ %tmp1813 = xor i32 %tmp1812, %tmp1811
+ store i32 %tmp1813, i32* %tmp1756, align 4
+; CHECK: store i32 -383584258, i32* %tmp114, align 4
+ %tmp2645 = getelementptr inbounds %2, %2* %tmp1, i64 0, i32 1
+ %tmp2650 = load i32, i32* %tmp2645, align 4
+ %tmp2655 = shl i32 %tmp2650, 5
+ %tmp2656 = xor i32 %tmp2655, %tmp2650
+ %tmp2657 = lshr i32 %tmp2656, 7
+ %tmp2658 = xor i32 %tmp2657, %tmp2656
+ %tmp2659 = shl i32 %tmp2658, 22
+ %tmp2660 = xor i32 %tmp2659, %tmp2658
+ %tmp2669 = shl i32 %tmp2660, 5
+ %tmp2670 = xor i32 %tmp2669, %tmp2660
+ %tmp2671 = lshr i32 %tmp2670, 7
+ %tmp2672 = xor i32 %tmp2671, %tmp2670
+ %tmp2673 = shl i32 %tmp2672, 22
+ %tmp2674 = xor i32 %tmp2673, %tmp2672
+ %tmp2683 = shl i32 %tmp2674, 5
+ %tmp2684 = xor i32 %tmp2683, %tmp2674
+ %tmp2685 = lshr i32 %tmp2684, 7
+ %tmp2686 = xor i32 %tmp2685, %tmp2684
+ %tmp2687 = shl i32 %tmp2686, 22
+ %tmp2688 = xor i32 %tmp2687, %tmp2686
+ %tmp2697 = shl i32 %tmp2688, 5
+ %tmp2698 = xor i32 %tmp2697, %tmp2688
+ %tmp2699 = lshr i32 %tmp2698, 7
+ %tmp2700 = xor i32 %tmp2699, %tmp2698
+ %tmp2701 = shl i32 %tmp2700, 22
+ %tmp2702 = xor i32 %tmp2701, %tmp2700
+ store i32 %tmp2702, i32* %tmp2645, align 4
+; CHECK: store i32 -57163022, i32* %tmp114, align 4
+ ret i32 0
+}
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