LLVM Bugzilla is read-only and represents the historical archive of all LLVM issues filled before November 26, 2021. Use github to submit LLVM bugs

Bug 45345 - Bad codegen: funclet Prologue and Epilogue do not agree on frame size.
Summary: Bad codegen: funclet Prologue and Epilogue do not agree on frame size.
Status: NEW
Alias: None
Product: libraries
Classification: Unclassified
Component: Backend: AArch64 (show other bugs)
Version: 9.0
Hardware: PC Windows NT
: P normal
Assignee: Unassigned LLVM Bugs
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-03-29 09:29 PDT by Daniel Frampton
Modified: 2020-03-29 09:44 PDT (History)
4 users (show)

See Also:
Fixed By Commit(s):

Attachments
Program that will crash if compiled and run on aarch64-pc-windows-msvc (288 bytes, text/plain)
2020-03-29 09:29 PDT, Daniel Frampton 		Details
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Daniel Frampton 2020-03-29 09:29:37 PDT 
Created attachment 23288 [details]
Program that will crash if compiled and run on aarch64-pc-windows-msvc

The generated code for a funclet can have an add to sp in the epilogue for which there is no corresponding sub in the prologue.

To trigger this case we must be generating a funclet and:

1) The function must make a call where arguments are passed on the stack (these are the extra bytes the epilog adds).

2) We must not be able to combine the stack adjustment into a single sub to sp when saving callee-save registers, which will happen if we have an aligned object or are using alloca.

Attaching simple C++ repro.

Bug exists in both LLVM9 and master.
Comment 1 Daniel Frampton 2020-03-29 09:44:17 PDT 
See https://reviews.llvm.org/D77015