Bug 109608 - Regression from llvm-6: llvm-7 replaces 'undef' with 'NaN', and generates NaN at the assembler level - This issue generates black screen on some fragment shaders.
Summary: Regression from llvm-6: llvm-7 replaces 'undef' with 'NaN', and generates NaN...
Status: NEW
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/Gallium/radeonsi (show other bugs)
Version: git
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Default DRI bug account
QA Contact: Default DRI bug account
Depends on:
Reported: 2019-02-11 14:47 UTC by Patrick
Modified: 2019-02-11 14:47 UTC (History)
0 users

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Description Patrick 2019-02-11 14:47:24 UTC
The issue is not related to mesa itself but at the LLVM optimization stage: LLVMRunPassManager(). This bug report is mostly for tracking purposes.

Here are two fragment shaders affected: https://www.shadertoy.com/view/ltl3WS and https://www.shadertoy.com/view/MdVcRd

Here is the LLVM bug report: https://bugs.llvm.org/show_bug.cgi?id=40690

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