Allow __ibm128 even if IEEE 128-bit floating point is not supported. This patch allows the use of the __ibm128 keyword on non-VSX systems. Originally, the __ibm128 keyword was only enabled when the IEEE 128-bit floating point is enabled. Sometime back in the GCC 12 development period, Segher asked that the __ibm128 keyword be allowed in older systems that don't support IEEE 128-bit. But at the time, stage 1 had closed for GCC 12, so I deferred doing this change until GCC 13. This patch allows __ibm128 to be used if either IEEE 128-bit is enabled or long double used the IBM 128-bit format.
I have tested these patches on the following systems: 1) LE Power10 using --with-cpu=power10 --with-long-double-format=ieee 2) LE Power10 using --with-cpu=power9 --with-long-double-format=ibm 3) LE Power10 using --with-cpu=power8 --with-long-double-format=ibm 4) LE Power10 using --with-cpu=power10 --with-long-double-format=ibm 5) LE Power9 using --with-cpu=power9 --with-long-double-format=ibm 6) BE Power8 using --with-cpu=power8 --with-long-double-format=ibm 7) BE Power8 using --with-cpu=power5 --with-long-double-format=ibm There were no regressions in the build or in the tests. Can I check this patch into the trunk? Did we want to backport this to earlier GCC releases? 2022-08-17 Michael Meissner <meiss...@linux.ibm.com> gcc/ * config/rs6000/rs6000-builtins.cc (rs6000_init_builtins): Enable using the__ibm128 keyword on systems that either use the 128-bit IBM long double format for long double or support IEEE 128-bit. * config/rs6000/rs6000.cc (rs6000_init_libfuncs): Create IBM 128-bit floating point support functions on systems that support the __ibm128 keyword. (rs6000_scalar_mode_supported_p): Likewise. * config/rs6000/rs6000.h (TARGET_IBM128): New macro. * config/rs6000/rs6000.md (@extenddf<mode>2_fprs): Allow IFmode to be converted even if long double is not 128-bits. (extenddf<mode>2_vsx): Likewise. (extendiftf2):Allow conversion on systems that support the __ibm128 keyword. (extendtfif2): Likewise. (trunciftf2): Likewise. (trunctfif2): Likewise. --- gcc/config/rs6000/rs6000-builtin.cc | 2 +- gcc/config/rs6000/rs6000.cc | 13 ++++++++----- gcc/config/rs6000/rs6000.h | 6 ++++++ gcc/config/rs6000/rs6000.md | 13 ++++++------- 4 files changed, 21 insertions(+), 13 deletions(-) diff --git a/gcc/config/rs6000/rs6000-builtin.cc b/gcc/config/rs6000/rs6000-builtin.cc index 12afa86854c..70680890415 100644 --- a/gcc/config/rs6000/rs6000-builtin.cc +++ b/gcc/config/rs6000/rs6000-builtin.cc @@ -713,7 +713,7 @@ rs6000_init_builtins (void) For IEEE 128-bit floating point, always create the type __ieee128. If the user used -mfloat128, rs6000-c.cc will create a define from __float128 to __ieee128. */ - if (TARGET_LONG_DOUBLE_128 && (!TARGET_IEEEQUAD || TARGET_FLOAT128_TYPE)) + if (TARGET_IBM128) { if (!TARGET_IEEEQUAD) ibm128_float_type_node = long_double_type_node; diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc index df491bee2ea..39527ce9bbc 100644 --- a/gcc/config/rs6000/rs6000.cc +++ b/gcc/config/rs6000/rs6000.cc @@ -11115,10 +11115,11 @@ rs6000_init_libfuncs (void) { /* __float128 support. */ if (TARGET_FLOAT128_TYPE) - { - init_float128_ibm (IFmode); - init_float128_ieee (KFmode); - } + init_float128_ieee (KFmode); + + /* __ibm128 support. */ + if (TARGET_IBM128) + init_float128_ibm (IFmode); /* AIX/Darwin/64-bit Linux quad floating point routines. */ if (TARGET_LONG_DOUBLE_128) @@ -23752,7 +23753,9 @@ rs6000_scalar_mode_supported_p (scalar_mode mode) if (DECIMAL_FLOAT_MODE_P (mode)) return default_decimal_float_supported_p (); - else if (TARGET_FLOAT128_TYPE && (mode == KFmode || mode == IFmode)) + else if (TARGET_FLOAT128_TYPE && mode == KFmode) + return true; + else if (TARGET_IBM128 && mode == IFmode) return true; else return default_scalar_mode_supported_p (mode); diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h index ad9bf0f7358..813ec696c0d 100644 --- a/gcc/config/rs6000/rs6000.h +++ b/gcc/config/rs6000/rs6000.h @@ -564,6 +564,12 @@ extern int rs6000_vector_align[]; && TARGET_P8_VECTOR \ && TARGET_POWERPC64) +/* Whether the __ibm128 keyword is allowed. Any system that supports _Float128 + is assumed to be capable of supporting __ibm128. Similarly if the long + double size is 128 bits, we assume __ibm128 is supported. We don't want to + support it on a system without existing 128-bit long doubles. */ +#define TARGET_IBM128 (TARGET_FLOAT128_TYPE || TARGET_LONG_DOUBLE_128) + /* Inlining allows targets to define the meanings of bits in target_info field of ipa_fn_summary by itself, the used bits for rs6000 are listed below. */ diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md index 1367a2cb779..f942597c3b4 100644 --- a/gcc/config/rs6000/rs6000.md +++ b/gcc/config/rs6000/rs6000.md @@ -8586,8 +8586,7 @@ (define_insn_and_split "@extenddf<mode>2_fprs" (float_extend:IBM128 (match_operand:DF 1 "nonimmediate_operand" "d,m,d"))) (use (match_operand:DF 2 "nonimmediate_operand" "m,m,d"))] - "!TARGET_VSX && TARGET_HARD_FLOAT - && TARGET_LONG_DOUBLE_128 && FLOAT128_IBM_P (<MODE>mode)" + "!TARGET_VSX && TARGET_HARD_FLOAT && FLOAT128_IBM_P (<MODE>mode)" "#" "&& reload_completed" [(set (match_dup 3) (match_dup 1)) @@ -8604,7 +8603,7 @@ (define_insn_and_split "@extenddf<mode>2_vsx" [(set (match_operand:IBM128 0 "gpc_reg_operand" "=d,d") (float_extend:IBM128 (match_operand:DF 1 "nonimmediate_operand" "wa,m")))] - "TARGET_LONG_DOUBLE_128 && TARGET_VSX && FLOAT128_IBM_P (<MODE>mode)" + "TARGET_VSX && FLOAT128_IBM_P (<MODE>mode)" "#" "&& reload_completed" [(set (match_dup 2) (match_dup 1)) @@ -9061,7 +9060,7 @@ (define_insn "*ieee_128bit_vsx_nabs<mode>2_internal" (define_expand "extendiftf2" [(set (match_operand:TF 0 "gpc_reg_operand") (float_extend:TF (match_operand:IF 1 "gpc_reg_operand")))] - "TARGET_FLOAT128_TYPE" + "TARGET_IBM128" { rs6000_expand_float128_convert (operands[0], operands[1], false); DONE; @@ -9088,7 +9087,7 @@ (define_expand "extendtfkf2" (define_expand "extendtfif2" [(set (match_operand:IF 0 "gpc_reg_operand") (float_extend:IF (match_operand:TF 1 "gpc_reg_operand")))] - "TARGET_FLOAT128_TYPE" + "TARGET_IBM128" { rs6000_expand_float128_convert (operands[0], operands[1], false); DONE; @@ -9097,7 +9096,7 @@ (define_expand "extendtfif2" (define_expand "trunciftf2" [(set (match_operand:TF 0 "gpc_reg_operand") (float_truncate:TF (match_operand:IF 1 "gpc_reg_operand")))] - "TARGET_FLOAT128_TYPE" + "TARGET_IBM128" { rs6000_expand_float128_convert (operands[0], operands[1], false); DONE; @@ -9124,7 +9123,7 @@ (define_expand "trunckftf2" (define_expand "trunctfif2" [(set (match_operand:IF 0 "gpc_reg_operand") (float_truncate:IF (match_operand:TF 1 "gpc_reg_operand")))] - "TARGET_FLOAT128_TYPE" + "TARGET_IBM128" { rs6000_expand_float128_convert (operands[0], operands[1], false); DONE; -- 2.37.2 -- Michael Meissner, IBM PO Box 98, Ayer, Massachusetts, USA, 01432 email: meiss...@linux.ibm.com