$ icc -fno-rounding-math
icc: internal error: Assertion failed (shared/driver/options.c, line 1684)
$ icc --version
icc (ICC) 14.0.2 20140120
This setting presumably is the default one (maybe not capable of alteration) for icc. Of course, internal error is a reportable bug.
It's unusual to see a compiler internal error with no input file specified (I can also reproduce the same error by providing one). Thanks for reporting this, I'll file a defect report with the developers.
Reported to the developers, tracking ID #DPD200254960. I'll keep this thread updated with any news.
The same error occurs on Mac OS as well.
Thanks for the feedback Jeff, I'll add Mac as an effected OS to the developer's problem report.
Apparently icc-14 is the first version to attempt to support -f[no-]rounding-math. icc-13.x just reports it as an 'unknown option'.
At least -frounding-math does work in icc-14:
$ icc -V -frounding-math fp_mantissa.c && ./a.out
Intel(R) C Intel(R) 64 Compiler XE for applications running on Intel(R) 64, Version 18.104.22.168 Build 20140120
Copyright (C) 1985-2014 Intel Corporation. All rights reserved.
Edison Design Group C/C++ Front End, version 4.6 (Jan 20 2014 19:26:22)
Copyright 1988-2013 Edison Design Group, Inc.
GNU ld version 22.214.171.124.2-5.28.el6 20091009