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From: Michael Meissner <meissner@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org Subject: [gcc(refs/users/meissner/heads/work099)] Update ChangeLog.meissner. Date: Thu, 1 Sep 2022 20:44:02 +0000 (GMT) [thread overview] Message-ID: <20220901204402.B48243858C83@sourceware.org> (raw) https://gcc.gnu.org/g:d1c8d84be6d6d01cb7452b2d9446ce934e77b4e6 commit d1c8d84be6d6d01cb7452b2d9446ce934e77b4e6 Author: Michael Meissner <meissner@linux.ibm.com> Date: Thu Sep 1 16:41:34 2022 -0400 Update ChangeLog.meissner. 2022-09-01 Michael Meissner <meissner@linux.ibm.com> gcc/ * ChangeLog.meissner: Update. Diff: --- gcc/ChangeLog.meissner | 138 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) diff --git a/gcc/ChangeLog.meissner b/gcc/ChangeLog.meissner index 18e33a2ebd5..ceca8ac003a 100644 --- a/gcc/ChangeLog.meissner +++ b/gcc/ChangeLog.meissner @@ -1,3 +1,141 @@ +==================== Work099, patch #4: +Rework 128-bit complex multiply and divide. + +This function reworks how the complex multiply and divide built-in functions are +done. Previously we created built-in declarations for doing long double complex +multiply and divide when long double is IEEE 128-bit. The old code also did not +support __ibm128 complex multiply and divide if long double is IEEE 128-bit. + +In terms of history, I wrote the original code just as I was starting to test +GCC on systems where IEEE 128-bit long double was the default. At the time, we +had not yet started mangling the built-in function names as a way to bridge +going from a system with 128-bit IBM long double to 128-bin IEEE long double. + +The original code depends on there only being two 128-bit types invovled. With +some of the changes that I plan on making, this assumption will no longer be +true in the future. + +The problem is we cannot create two separate built-in functions that resolve to +the same name. This is a requirement of add_builtin_function and the C front +end. That means for the 3 possible modes (IFmode, KFmode, and TFmode), you can +only use 2 of them. + +This code does not create the built-in declaration with the changed name. +Instead, it uses the TARGET_MANGLE_DECL_ASSEMBLER_NAME hook to change the name +before it is written out to the assembler file like it now does for all of the +other long double built-in functions. + +We need to disable using this mapping when we are building libgcc, which is +creating the multiply and divide functions. The flag that is used when libgcc +is built (-fbuilding-libcc) is only available in the C/C++ front ends. We need +to remember that we are building libgcc in the rs6000-c.cc support to be able to +use this later to decided whether to mangle the decl assembler name or not. + +When I wrote these patches, I discovered that __ibm128 complex multiply and +divide had originally not been supported if long double is IEEE 128-bit as it +would generate calls to __mulic3 and __divic3. I added tests in the testsuite +to verify that the correct name (i.e. __multc3 and __divtc3) is used in this +case. + +2022-09-01 Michael Meissner <meissner@linux.ibm.com> + +gcc/ + + * config/rs6000/rs6000-c.cc (rs6000_cpu_cpp_builtins): Set + building_libgcc. + * config/rs6000/rs6000.cc (create_complex_muldiv): Delete. + (init_float128_ieee): Delete code to switch complex multiply and divide + for long double. + (complex_multiply_builtin_code): New helper function. + (complex_divide_builtin_code): Likewise. + (rs6000_mangle_decl_assembler_name): Add support for mangling the name + of complex 128-bit multiply and divide built-in functions. + * config/rs6000/rs6000.opt (building_libgcc): New target variable. + +gcc/testsuite/ + + * gcc.target/powerpc/divic3-1.c: New test. + * gcc.target/powerpc/divic3-2.c: Likewise. + * gcc.target/powerpc/mulic3-1.c: Likewise. + * gcc.target/powerpc/mulic3-2.c: Likewise. + +==================== Work099, patch #3: + +Add 'w' suffix for __ibm128 constants. + +In the documentation, we mention that 'w' or 'W' can be used as a suffix for +__ibm128 constants. We never implemented this. This patch fixes that. + +In addition, the 'q' and 'Q' suffix were changed to use the mode used for the +__float128 type, instead of knowing whether to use KFmode or TFmode explicitly. +This will be used in a future patch where we change the mode used for __float128 +on systems where long double is IEEE 128-bit. + +2022-09-01 Michael Meissner <meissner@linux.ibm.com> + +gcc/ + + * config/rs6000/rs6000.cc (rs6000_c_mode_for_suffix): Allow 'w' or 'W' + for __ibm128 constants. + +gcc/testsuite/ + + * gcc.target/powerpc/ibm128-suffix.c: New test. + +==================== Work099, patch #2: + +Allow __ibm128 with -msoft-float (PR target/105334) + +This patch allows __ibm128 to be used on systems with software floating point +enabled. Previously, we required hardware floating point to be enabled to use +__ibm128 keyword and the __ibm128 built-in functions. This patch fixes PR +target/105334. + +2022-09-01 Michael Meissner <meissner@linux.ibm.com> + +gcc/ + + PR target/105334 + * config/rs6000/rs6000.cc (init_float128_ibm): Do not require hardware + floating point for the IBM 128-bit floating point comparison functions. + * config/rs6000/rs6000.h (FLOAT128_IBM_P): Do not require hardware + floating point to enable recognizing IBM 128-bit floating point modes. + +==================== Work099, patch #1: + +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. + +2022-09-01 Michael Meissner <meissner@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. + +==================== Work099, branch head + 2022-09-01 Michael Meissner <meissner@linux.ibm.com> Clone branch
next reply other threads:[~2022-09-01 20:44 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-09-01 20:44 Michael Meissner [this message] 2022-09-02 2:24 Michael Meissner 2022-09-02 6:40 Michael Meissner
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