Compilers - Revision history

Jrwrigh at 16:34, 12 February 2020

2020-02-12T16:34:10Z

Matthb2: /* Portland */

2012-11-22T07:55:52Z

‎Portland

Matthb2: /* Intel */

2012-09-29T00:39:10Z

‎Intel

Matthb2: /* Intel */

2012-09-29T00:34:23Z

‎Intel

Matthb2 at 00:33, 29 September 2012

2012-09-29T00:33:44Z

Matthb2: Created page with "We have access to several different sets of compilers and libraries. Ideally your code should work with all of them, and you can test which produces the fastest executables. Some..."

2012-09-29T00:16:52Z

Created page with "We have access to several different sets of compilers and libraries. Ideally your code should work with all of them, and you can test which produces the fastest executables. Some..."

New page

We have access to several different sets of compilers and libraries. Ideally your code should work with all of them, and you can test which produces the fastest executables. Some also have different debugging features.

==GNU==
The GNU toolchain is the standard in the open source world and tends to be the most compatible (at least for C/C++ code). Several versions which ship with the operating system should be available by default and can be invoked as:
gcc #C code
g++ #C++ code
gfortran #F77, F90

To compile with debug support add at least
-g
to your compile flags. Adding
-g -O0 -fno-omit-frame-pointer -fbounds-check -ftrapv

may make the code easier to debug. See the manpages for language specific options.

To generate an optimized build start with
-O3
and see the manpage for more optional optimizations.

There are also some newer versions available using the softenv tool. Note that if you use a newer GNU toolchain, you should also have it loaded into your environment at runtime to ensure that the correct libraries are used.

==Intel==
The Intel toolchain typically generates fast executables for Intel processors. It also ships with some debugging and profiling tools. You can load the Intel toolchain by executing:

soft add +intelcompilers-64bit

There are some known issues with debugging Fortran code (particularly if it uses dynamically allocated arrays) using the Intel toolchain.

← Older revision		Revision as of 16:34, 12 February 2020
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		+	[[Category:Software Engineering]]
		+
	We have access to several different sets of compilers and libraries. Ideally your code should work with all of them, and you can test which produces the fastest executables. Some also have different debugging features.		We have access to several different sets of compilers and libraries. Ideally your code should work with all of them, and you can test which produces the fastest executables. Some also have different debugging features.

@@ Line 63: / Line 63: @@
    pgf77 #F77
 Note that PGI 11.x has some bad C++ related bugs. You should use PGI 12 or newer.
 ==LLVM/Clang==

@@ Line 30: / Line 30: @@
    ifort #F90/F77/F2003
-There are some known issues with debugging Fortran code (particularly if it uses dynamically allocated arrays)  using the Intel toolchain.
+There are some known issues with debugging Fortran code (particularly if it uses dynamically allocated arrays)  using the Intel toolchain. These bugs seem to be fixed in the release version of Intel 2013, which is starting to become available on some machines (not ours yet)
 For debugging, you need at a minimum

@@ Line 41: / Line 41: @@
    -O3
 and check the manpage for more options.
 The Intel debugger is called

← Older revision		Revision as of 00:33, 29 September 2012
Line 24:		Line 24:

	soft add +intelcompilers-64bit		soft add +intelcompilers-64bit
		+
		+	You can then invoke
		+	icc #C
		+	icpc #C++
		+	ifort #F90/F77/F2003

	There are some known issues with debugging Fortran code (particularly if it uses dynamically allocated arrays) using the Intel toolchain.		There are some known issues with debugging Fortran code (particularly if it uses dynamically allocated arrays) using the Intel toolchain.
		+
		+	For debugging, you need at a minimum
		+	-g
		+
		+	For best results, try
		+	-O0 -debug all -fstack-protector -no-ipo -g
		+
		+	For an optimized build, start with:
		+	-O3
		+	and check the manpage for more options.
		+
		+	The Intel debugger is called
		+	idb
		+
		+	(but note that it consumes a license for the entire compiler suite, so please don't leave it running for long periods of time)
		+
		+	==Portland==
		+	The PGI toolchain is an alternative toolchain, with which we have had good luck debugging Fortran codes. It also supports OpenACC (like OpenMP for GPUs)
		+
		+	You can load the PGI compilers by running
		+	soft add +pgi-64bit
		+
		+	and invoke them as
		+	pgcc #C
		+	pgCC #C++
		+	pgfortran #various Fortran
		+	pgf90 #F90
		+	pgf77 #F77
		+
		+	Note that PGI 11.x has some bad C++ related bugs. You should use PGI 12 or newer.
		+
		+	==LLVM/Clang==
		+	soft add @llvm-3.2svn
		+
		+	==LLVM/Dragonegg==