RPCS3/llvm
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm.git synced 2024-11-24 12:20:00 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

LoopVectorize: Fix a bug in the initialization of reduction variables. AND needs to start at all-one

Browse Source 
while XOR, and OR need to start at zero.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167032 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nadav Rotem 2012-10-30 18:12:36 +00:00
parent c197a55019
commit cc03331caa
2 changed files with 22 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
lib/Transforms/Vectorize/LoopVectorize.cpp
View File

@ -211,8 +211,6 @@ public:
TheLoop(Lp), SE(Se), DL(Dl), Induction(0) { }
/// This represents the kinds of reductions that we support.
/// We use the enum values to hold the 'identity' value for
/// each operand. This value does not change the result if applied.
enum ReductionKind {
NoReduction = -1, /// Not a reduction.
IntegerAdd = 0, /// Sum of numbers.
@ -523,7 +521,7 @@ SingleBlockLoopVectorizer::getUniformVector(unsigned Val, Type* ScalarTy) {
SmallVector<Constant*, 8> Indices;
// Create a vector of consecutive numbers from zero to VF.
for (unsigned i = 0; i < VF; ++i)
Indices.push_back(ConstantInt::get(ScalarTy, Val));
Indices.push_back(ConstantInt::get(ScalarTy, Val, true));
// Add the consecutive indices to the vector value.
return ConstantVector::get(Indices);
@ -750,6 +748,23 @@ SingleBlockLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) {
LoopBypassBlock = BypassBlock;
}
static unsigned
getReductionIdentity(LoopVectorizationLegality::ReductionKind K) {
switch (K) {
case LoopVectorizationLegality::IntegerXor:
case LoopVectorizationLegality::IntegerAdd:
case LoopVectorizationLegality::IntegerOr:
return 0;
case LoopVectorizationLegality::IntegerMult:
return 1;
case LoopVectorizationLegality::IntegerAnd:
return -1;
default:
llvm_unreachable("Unknown reduction kind");
}
}
void
SingleBlockLoopVectorizer::vectorizeLoop(LoopVectorizationLegality *Legal) {
//===------------------------------------------------===//
@ -974,10 +989,9 @@ SingleBlockLoopVectorizer::vectorizeLoop(LoopVectorizationLegality *Legal) {
Value *VectorExit = getVectorValue(RdxDesc.LoopExitInstr);
Type *VecTy = VectorExit->getType();
// Find the reduction identity variable. The value of the enum is the
// identity. Zero for addition. One for Multiplication.
unsigned IdentitySclr = RdxDesc.Kind;
Constant *Identity = getUniformVector(IdentitySclr,
// Find the reduction identity variable. Zero for addition, or, xor,
// one for multiplication, -1 for And.
Constant *Identity = getUniformVector(getReductionIdentity(RdxDesc.Kind),
VecTy->getScalarType());
// This vector is the Identity vector where the first element is the

1
test/Transforms/LoopVectorize/reduction.ll
View File

@ -151,6 +151,7 @@ for.end: ; preds = %for.body, %entry
;CHECK: @reduction_and
;CHECK: and <4 x i32>
;CHECK: <i32 -1, i32 -1, i32 -1, i32 -1>
;CHECK: ret i32
define i32 @reduction_and(i32 %n, i32* nocapture %A, i32* nocapture %B) nounwind uwtable readonly {
entry: