Bug 229444
Summary: | gcc and sse2 intrins does not correctly compile with -O<1, 2, 3, s> optimization flags | ||||||
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Product: | [Fedora] Fedora | Reporter: | Steve <steve.t.armstrong> | ||||
Component: | gcc4 | Assignee: | Jakub Jelinek <jakub> | ||||
Status: | CLOSED NOTABUG | QA Contact: | |||||
Severity: | medium | Docs Contact: | |||||
Priority: | medium | ||||||
Version: | 6 | ||||||
Target Milestone: | --- | ||||||
Target Release: | --- | ||||||
Hardware: | All | ||||||
OS: | Linux | ||||||
Whiteboard: | |||||||
Fixed In Version: | Doc Type: | Bug Fix | |||||
Doc Text: | Story Points: | --- | |||||
Clone Of: | Environment: | ||||||
Last Closed: | 2007-02-21 08:11:10 UTC | Type: | --- | ||||
Regression: | --- | Mount Type: | --- | ||||
Documentation: | --- | CRM: | |||||
Verified Versions: | Category: | --- | |||||
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
Cloudforms Team: | --- | Target Upstream Version: | |||||
Embargoed: | |||||||
Attachments: |
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Description
Steve
2007-02-21 04:21:39 UTC
Created attachment 148465 [details]
a very very small c program with sse2 instructions
They are optimized away as useless, as written in the testcase they don't have any visible side effect, the results are stored into an automatic variable. If you don't want them to be optimized away, you need to either store at least the final result to a non-automatic variable, return from function, pass to other function (e.g. print them). Oh, I didn't realize the compiler would automatically disregard the sse2 if they are useless instructions, I guess that's a good thing then. |