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3 Commits

Author SHA1 Message Date
David Spickett 1d51c699b9 [clang][Arm] Fix handling of -Wa,-march=
This fixes Bugzilla #48894 for Arm, where it
was reported that -Wa,-march was not being handled
by the integrated assembler.

This was previously fixed for -Wa,-mthumb by
parsing the argument in ToolChain::ComputeLLVMTriple
instead of CollectArgsForIntegratedAssembler.
It has to be done in the former because the Triple
is read only by the time we get to the latter.

Previously only mcpu would work via -Wa but only because
"-target-cpu" is it's own option to cc1, which we were
able to modify. Target architecture is part of "-target-triple".

This change applies the same workaround to -march and cleans up
handling of -Wa,-mcpu at the same time. There were some
places where we were not using the last instance of an argument.

The existing -Wa,-mthumb code was doing this correctly,
so I've just added tests to confirm that.

Now the same rules will apply to -Wa,-march/-mcpu as would
if you just passed them to the compiler:
* -Wa/-Xassembler options only apply to assembly files.
* Architecture derived from mcpu beats any march options.
* When there are multiple mcpu or multiple march, the last
  one wins.
* If there is a compiler option and an assembler option of
  the same type, we prefer the one that fits the input type.
* If there is an applicable mcpu option but it is overruled
  by an march, the cpu value is still used for the "-target-cpu"
  cc1 option.

Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D95872
2021-02-04 16:36:15 +00:00
Petr Hosek 7b27454477 [ADT] Normalize empty triple components
LLVM triple normalization is handling "unknown" and empty components
differently; for example given "x86_64-unknown-linux-gnu" and
"x86_64-linux-gnu" which should be equivalent, triple normalization
returns "x86_64-unknown-linux-gnu" and "x86_64--linux-gnu". autoconf's
config.sub returns "x86_64-unknown-linux-gnu" for both
"x86_64-linux-gnu" and "x86_64-unknown-linux-gnu". This changes the
triple normalization to behave the same way, replacing empty triple
components with "unknown".

This addresses PR37129.

Differential Revision: https://reviews.llvm.org/D50219

llvm-svn: 339294
2018-08-08 22:23:57 +00:00
Peter Smith 3947cb3cf0 [ARM] For assembler files recognize -Xassembler or -Wa, -mthumb
The Unified Arm Assembler Language is designed so that the majority of
assembler files can be assembled for both Arm and Thumb with the choice
made as a compilation option.

The way this is done in gcc is to pass -mthumb to the assembler with either
-Wa,-mthumb or -Xassembler -mthumb. This change adds support for these
options to clang. There is no assembler equivalent of -mno-thumb, -marm or
-mno-arm so we don't need to recognize these.

Ideally we would do all of the processing in
CollectArgsForIntegratedAssembler(). Unfortunately we need to change the
triple and at that point it is too late. Instead we look for the option
earlier in ComputeLLVMTriple().
    
Fixes PR34519
    
Differential Revision: https://reviews.llvm.org/D40127

llvm-svn: 318647
2017-11-20 13:43:55 +00:00