Red Hat Bugzilla – Bug 52554
g77 -O2 -c serf.f causes internal compiler error
Last modified: 2007-04-18 12:36:35 EDT
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Description of problem:
Compilation of one particular routine by g77 with -O2 causes internal error report, no output.
-O1 or less works, -O3 fails. This same compilation line worked under RH6.2.
You can have the source (see attachment).
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. g77 -c -O2 serf.f
Actual Results: > g77 -c -O2 serf.f
serf.f: In function `serf':
serf.f:453: Internal compiler error in convert_regs_1, at reg-stack.c:2607
Expected Results: should have produced serf.o
Name : gcc-g77 Relocations: (not relocateable)
Version : 2.96 Vendor: Red Hat, Inc.
Release : 85 Build Date: Wed 09 May 2001 11:04:50 AM PDT
Created attachment 29454 [details]
very old fortran file: single prec error fcn from math77
Seems gcse is messing up the flow graph. The bug is present in g77 3.0.1 too,
bug apparently at least not reproduceable in g77 3.1 CVS.
Simple workaround -fno-gcse. Debugging...
Ok in 3.2