Teach getSmallConstantTripMultiple about Shl operators.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89426 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2009-11-20 01:09:34 +00:00
parent 9ef4835bd8
commit ac146657fc
2 changed files with 33 additions and 0 deletions

View File

@ -243,6 +243,11 @@ unsigned Loop::getSmallConstantTripMultiple() const {
case BinaryOperator::Mul:
Result = dyn_cast<ConstantInt>(BO->getOperand(1));
break;
case BinaryOperator::Shl:
if (ConstantInt *CI = dyn_cast<ConstantInt>(BO->getOperand(1)))
if (CI->getValue().getActiveBits() <= 5)
return 1u << CI->getZExtValue();
break;
default:
break;
}

View File

@ -0,0 +1,28 @@
; RUN: opt < %s -loop-unroll -unroll-count=2 -S | FileCheck %s
; LoopUnroll should unroll this loop into one big basic block.
; CHECK: for.body:
; CHECK: %i.013 = phi i64 [ 0, %entry ], [ %tmp16.1, %for.body ]
; CHECK: br i1 %exitcond.1, label %for.end, label %for.body
define void @foo(double* nocapture %p, i64 %n) nounwind {
entry:
%mul10 = shl i64 %n, 1 ; <i64> [#uses=2]
br label %for.body
for.body: ; preds = %entry, %for.body
%i.013 = phi i64 [ %tmp16, %for.body ], [ 0, %entry ] ; <i64> [#uses=2]
%arrayidx7 = getelementptr double* %p, i64 %i.013 ; <double*> [#uses=2]
%tmp16 = add i64 %i.013, 1 ; <i64> [#uses=3]
%arrayidx = getelementptr double* %p, i64 %tmp16 ; <double*> [#uses=1]
%tmp4 = load double* %arrayidx ; <double> [#uses=1]
%tmp8 = load double* %arrayidx7 ; <double> [#uses=1]
%mul9 = fmul double %tmp8, %tmp4 ; <double> [#uses=1]
store double %mul9, double* %arrayidx7
%exitcond = icmp eq i64 %tmp16, %mul10 ; <i1> [#uses=1]
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body, %entry
ret void
}