[SR-7310] Xcode 9.3 fails to compile complex expressions (too complex)

[swift-ci]

Previous ID	SR-7310
Radar	None
Original Reporter	Thieme (JIRA User)
Type	Bug

Attachment: Download

Environment

macOS 10.13.4

Xcode 9.3

Additional Detail from JIRA

Votes	0
Component/s	Compiler, Standard Library
Labels	Bug, 4.1Regression, TypeChecker
Assignee	@xedin
Priority	Medium

md5: 77ad85e7a0279c1678bd39d5a39797cc

Issue Description:

While the attached code fragment compiles fine in Xcode 9.2, compilation using Xcode 9.3 fails with the message:

expression was too complex to be solved in reasonable time; consider breaking up the expression into distinct sub-expressions

Example:

if df2 > 8.0 {
{{ result.kurtosis = 3.0 + (12 * (pow(df2 - 2,2.0) * (df2 - 4) + df1 * (df1 + df2 - 2.0) * (5.0 * df2 - 22))) / (df1 * (df2 - 6) * (df2 - 8) * (df1 + df2 - 2))}}
{{}}}

[swift-ci]

Comment by Volker Thieme (JIRA)

Compilation fails even in playground.

[belkadan]

cc @rudkx, @xedin

[xedin]

Thanks for the report, Thieme (JIRA User)! We are working on trying to fix performance issues related to operator chaining.