Re: [PATCH], Add power9 support to GCC, patch #5 (ISA 3.0 fusion)

[David Edelsohn <dje.gcc@gmail.com>]

On Sun, Nov 8, 2015 at 4:42 PM, Michael Meissner
<meissner@linux.vnet.ibm.com> wrote:
> This patch adds support for new fusion forms in ISA 3.0 (power9).  In
> particular, ISA 3.0 can fuse GPR loads of R0, FPR loads, GPR stores, FPR
> stores, and some constant generation that ISA 2.07 (power8) could not
> generate.
>
> I have built this patch with a bootstrap build on a power8 little endian
> system.  There were no regressions in the test suite.  Is this patch ok to
> install in the trunk once patch #1 has been installed.
>
> [gcc]
> 2015-11-08  Michael Meissner  <meissner@linux.vnet.ibm.com>
>
>         * config/rs6000/constraints.md (wF constraint): New constraints
>         for power9/toc fusion.
>         (wG constraint): Likewise.
>
>         * config/rs6000/predicates.md (upper16_cint_operand): New
>         predicate for power9 and toc fusion.
>         (fpr_reg_operand): Likewise.
>         (toc_fusion_or_p9_reg_operand): Likewise.
>         (toc_fusion_mem_raw): Likewise.
>         (toc_fusion_mem_wrapped): Likewise.
>         (fusion_gpr_addis): If power9 fusion, allow fusion for a larger
>         address range.
>         (fusion_gpr_mem_combo): Delete, use fusion_addis_mem_combo_load
>         instead.
>         (fusion_addis_mem_combo_load): Add support for power9 fusion of
>         floating point loads, floating point stores, and gpr stores.
>         (fusion_addis_mem_combo_store): Likewise.
>         (fusion_offsettable_mem_operand): Likewise.
>
>         * config/rs6000/rs6000-protos.h (emit_fusion_addis): Add
>         declarations.
>         (emit_fusion_load_store): Likewise.
>         (fusion_p9_p): Likewise.
>         (expand_fusion_p9_load): Likewise.
>         (expand_fusion_p9_store): Likewise.
>         (emit_fusion_p9_load): Likewise.
>         (emit_fusion_p9_store): Likewise.
>         (fusion_wrap_memory_address): Likewise.
>
>         * config/rs6000/rs6000.c (struct rs6000_reg_addr): Add new
>         elements for power9 fusion.
>         (rs6000_debug_print_mode): Rework debug information to print more
>         information about fusion.
>         (rs6000_init_hard_regno_mode_ok): Setup for power9 fusion
>         support.
>         (rs6000_legitimate_address_p): Recognize toc fusion as a valid
>         offsettable memory address.
>         (emit_fusion_gpr_load): Move most of the code from
>         emit_fusion_gpr_load into emit_fusion-addis that handles both
>         power8 and power9 fusion.
>         (emit_fusion_addis): Likewise.
>         (emit_fusion_load_store): Likewise.
>         (fusion_wrap_memory_address): Add support for TOC fusion.
>         (fusion_split_address): Likewise.
>         (fusion_p9_p): Add support for power9 fusion.
>         (expand_fusion_p9_load): Likewise.
>         (expand_fusion_p9_store): Likewise.
>         (emit_fusion_p9_load): Likewise.
>         (emit_fusion_p9_store): Likewise.
>
>         * config/rs6000/rs6000.h (TARGET_TOC_FUSION_INT): New macros for
>         power9 fusion support.
>         (TARGET_TOC_FUSION_FP): Likewise.
>
>         * config/rs6000/rs6000.md (UNSPEC_FUSION_P9): New power9/toc
>         fusion unspecs.
>         (UNSPEC_FUSION_ADDIS): Likewise.
>         (QHSI mode iterator): New iterator for power9 fusion.
>         (GPR_FUSION): Likewise.
>         (FPR_FUSION): Likewise.
>         (power9 fusion splitter): New power9/toc fusion support.
>         (toc_fusionload_<mode>): Likewise.
>         (toc_fusionload_di): Likewise.
>         (fusion_gpr_load_<mode>): Update predicate function.
>         (power9 fusion peephole2s): New power9/toc fusion support.
>         (fusion_gpr_<P:mode>_<GPR_FUSION:mode>_load): Likewise.
>         (fusion_gpr_<P:mode>_<GPR_FUSION:mode>_store): Likewise.
>         (fusion_fpr_<P:mode>_<FPR_FUSION:mode>_load): Likewise.
>         (fusion_fpr_<P:mode>_<FPR_FUSION:mode>_store): Likewise.
>         (fusion_p9_<mode>_constant): Likewise.
>
> [gcc/testsuite]
> 2015-11-08  Michael Meissner  <meissner@linux.vnet.ibm.com>
>
>         * gcc.target/powerpc/fusion.c (fusion_vector): Move to fusion2.c
>         and allow the test on PowerPC LE.
>         * gcc.target/powerpc/fusion2.c (fusion_vector): Likewise.
>
>         * gcc.target/powerpc/fusion3.c: New file, test power9 fusion.

Okay, with the changes that you and Segher discussed.

Thanks, David