Bug 694270

Summary:	[6.2 FEAT] gcc enhancements for more efficient floating point code generation
Product:	Red Hat Enterprise Linux 6	Reporter:	IBM Bug Proxy <bugproxy>
Component:	gcc	Assignee:	Jakub Jelinek <jakub>
Status:	CLOSED WONTFIX	QA Contact:	qe-baseos-tools-bugs
Severity:	high	Docs Contact:
Priority:	high
Version:	6.2	CC:	jjarvis, nobody+PNT0273897, sbest
Target Milestone:	beta	Keywords:	FutureFeature, OtherQA
Target Release:	6.2
Hardware:	ppc64
OS:	All
Whiteboard:
Fixed In Version:		Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-06-08 18:17:50 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Bug Depends On:
Bug Blocks:	638197, 659725

Description IBM Bug Proxy 2011-04-06 20:32:35 UTC

1. Feature Overview:
Feature Id: [71193]
a. Name of Feature: [6.2 FEAT] gcc enhancements for more efficient floating point code generation
b. Feature Description
gcc enhancement for more efficient floating point code generation:
*Provide optimizations specifically directed at improving floating point intensive software running
on POWER hardware
* Add -mveclibabi=mass support
* improve code generation of copysign and parity on power6/power7 systems
* improve code generation of pow (x, 0.75) under fast math (machine independent change)
* add -mrecip switch to use the reciprocal estimate instructions

2. Feature Details:
Sponsor: LTC Toolchain
Architectures:  ppc64, 
Arch Specificity: both
Affects Kernel Modules: No
Delivery Mechanism: Backport
Category: other
Request Type: Package - Feature from IBM
d. Upstream Acceptance: Accepted
Sponsor Priority P2
f. Severity: high
IBM Confidential: No
Code Contribution: IBM code
g. Component Version Target: ---

3. Business Case
Improved floating point SPEC benchmarks by 10 - 15% will improve sales of Power hardware on RHEL

4. Primary contact at Red Hat:
John Jarvis, jjarvis

5. Primary contacts at Partner:
Project Management Contact:
Michael L. Hohnbaum, hbaum.com

Technical contact(s):
MICHAEL R. MEISSNER, mrmeissn.com

Comment 2 RHEL Program Management 2011-04-06 20:44:10 UTC

Since RHEL 6.1 External Beta has begun, and this bug remains
unresolved, it has been rejected as it is not proposed as
exception or blocker.

Red Hat invites you to ask your support representative to
propose this request, if appropriate and relevant, in the
next release of Red Hat Enterprise Linux.

Comment 3 John Jarvis 2011-04-27 17:53:04 UTC

IBM is signed up to test and provide feedback, setting OtherQA.

Comment 4 IBM Bug Proxy 2011-05-24 16:50:23 UTC

------- Comment From hohnbaum.com 2011-05-24 12:46 EDT-------
Due to the difficulty in backporting this feature (requires bringing along several updates to support the specific item) compared to the expected benefit, the IBM Power Toolchain team has decided to quit this feature.