Pull in r248439 from upstream llvm trunk (by Sanjay Patel):
set div/rem default values to 'expensive' in TargetTransformInfo's cost model ...because that's what the cost model was intended to do. As discussed in D12882, this fix has a temporary unintended consequence for SimplifyCFG: it causes us to not speculate an fdiv. However, two wrongs make PR24818 right, and two wrongs make PR24343 act right even though it's really still wrong. I intend to correct SimplifyCFG and add to CodeGenPrepare to account for this cost model change and preserve the righteousness for the bug report cases. https://llvm.org/bugs/show_bug.cgi?id=24818 https://llvm.org/bugs/show_bug.cgi?id=24343 Differential Revision: http://reviews.llvm.org/D12882 This fixes the too-eager fdiv hoisting in pow(), which could lead to unexpected floating point exceptions.
This commit is contained in:
parent
8c4d4936be
commit
a502cd2f72
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/projects/clang370-import/; revision=288195
@ -60,6 +60,14 @@ class TargetTransformInfoImplBase {
|
||||
// Otherwise, the default basic cost is used.
|
||||
return TTI::TCC_Basic;
|
||||
|
||||
case Instruction::FDiv:
|
||||
case Instruction::FRem:
|
||||
case Instruction::SDiv:
|
||||
case Instruction::SRem:
|
||||
case Instruction::UDiv:
|
||||
case Instruction::URem:
|
||||
return TTI::TCC_Expensive;
|
||||
|
||||
case Instruction::IntToPtr: {
|
||||
// An inttoptr cast is free so long as the input is a legal integer type
|
||||
// which doesn't contain values outside the range of a pointer.
|
||||
|
Loading…
Reference in New Issue
Block a user