This commit amalgamates a patch set proposed by Jens Remus to enable the
SFrame Version 3 Flexible FDE Type (SFRAME_FDE_TYPE_FLEX) generation for
the s390x ABI.
Previously, s390x relied on architecture-specific encoding (shifting register
numbers into offset fields) to represent register recovery rules. This limited
the complexity of CFI that could be supported. With Flex FDE enabled:
- s390x can now represent .cfi_def_cfa using non-SP/FP registers.
- The architecture-specific function s390_sframe_xlate_do_register () in GAS
is replaced by the generic Flex FDE generation path.
- The SFrame V3 specific macros for s390x register encoding are removed
from libsframe/include, as the generic Flex FDE format handles explicit
register columns natively.
The testsuite is updated to replace negative tests (which asserted
warnings or empty SFrame generation for these patterns) with positive
tests verifying valid Flex FDE generation.
Co-authored-by: Jens Remus <jremus@linux.ibm.com>
gas/
* config/tc-s390.c (s390_support_flex_fde_p): Return true to
enable Flex FDE generation.
* gen-sframe.c (s390_sframe_xlate_do_register): Disable s390x
specific implementation.
(sframe_xlate_do_register): Invoke generic Flex FDE path now
that flex FDE generation is supported.
gas/testsuite/
* gas/cfi-sframe/cfi-sframe-s390x-err-1.d: Removed.
* gas/cfi-sframe/cfi-sframe-s390x-err-1.s: Moved to...
* gas/cfi-sframe/cfi-sframe-s390x-non-spfp-cfa-1.s: ...here.
* gas/cfi-sframe/cfi-sframe-s390x-err-2.d: Removed.
* gas/cfi-sframe/cfi-sframe-s390x-err-2.s: Moved to...
* gas/cfi-sframe/cfi-sframe-s390x-non-spfp-cfa-2.s: ...here.
* gas/cfi-sframe/cfi-sframe-s390x-fpra-register-1.d: Update to
expect Flex FDE output.
* gas/cfi-sframe/cfi-sframe-s390x-fpra-register-2.d: Likewise.
* gas/cfi-sframe/cfi-sframe.exp: Run renamed tests.
include/
* sframe.h (SFRAME_V3_S390X_OFFSET_IS_REGNUM): Remove.
(SFRAME_V3_S390X_OFFSET_ENCODE_REGNUM): Remove.
(SFRAME_V3_S390X_OFFSET_DECODE_REGNUM): Remove.
libsframe/
* sframe-dump.c (sframe_s390x_offset_regnum_p): Return false
for SFrame V3.
(sframe_s390x_offset_decode_regnum): Remove V3 support.
c1929fda66