S/390 And Zseries Options - Red Hat ENTERPRISE LINUX 3 - USING GCC Using Instructions

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-mearly-stop-bits
-mno-early-stop-bits
Allow stop bits to be placed earlier than immediately preceding the instruction that triggered the
stop bit. This can improve instruction scheduling, but does not always do so.

4.17.5. S/390 and zSeries Options

These are the options defined for the S/390 and zSeries architecture.
-m
-mhard-float
-msoft-float
Use (do not use) the hardware floating-point instructions and registers for floating-point
operations. When
floating-point operations. When
floating-point instructions. This is the default.
-mbackchain
-mno-backchain
Generate (or do not generate) code which maintains an explicit backchain within the stack frame
that points to the caller's frame. This is currently needed to allow debugging. The default is to
generate the backchain.
-msmall-exec
-mno-small-exec
Generate (or do not generate) code using the
works reliably if the total executable size does not exceed 64k. The default is to use the
instruction instead, which does not have this limitation.
-m64
-m31
When is specified, generate code compliant to the Linux for S/390 ABI. When
-m31
specified, generate code compliant to the Linux for zSeries ABI. This allows GCC in particular
to generate 64-bit instructions. For the
default to .
-m64
-mzarch
-mesa
When
-mzarch
When is specified, generate code using the instructions available on ESA/390. Note that
-mesa
is not possible with
-mesa
targets default to
-mmvcle
-mno-mvcle
Generate (or do not generate) code using the
is specified, use a
-mno-mvcle
-mdebug
-mno-debug
Print (or do not print) additional debug information when compiling. The default is to not print
debug information.
is specified, functions in
-msoft-float
-mhard-float
is specified, generate code using the instructions available on z/Architecture.
. For the
-m64
.
-mzarch
loop instead. This is the default.
mvc
Chapter 4. GCC Command Options
is specified, the compiler generates IEEE
instruction to do subroutine calls. This only
bras
targets, the default is
s390
targets, the default is
s390
instruction to perform block moves. When
mvcle
will be used to perform
libgcc.a
, while the
-m31
, while the
-mesa
basr
is
-m64
targets
s390x
s390x