[Bug target/100108] [10/11 Regression] powerpc: recognize 32-bit CPU as POWER9 with -misel option

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100108

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dje at gcc dot gnu.org,
                   |                            |jakub at gcc dot gnu.org,
                   |                            |segher at gcc dot gnu.org

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Indeed, several rs6000-cpus.def entries have MASK_ISEL:
RS6000_CPU ("8540", PROCESSOR_PPC8540, MASK_STRICT_ALIGN | MASK_ISEL)
RS6000_CPU ("8548", PROCESSOR_PPC8548, MASK_STRICT_ALIGN | MASK_ISEL)
RS6000_CPU ("e500mc", PROCESSOR_PPCE500MC, MASK_PPC_GFXOPT | MASK_ISEL)
RS6000_CPU ("e500mc64", PROCESSOR_PPCE500MC64,
            MASK_POWERPC64 | MASK_PPC_GFXOPT | MASK_ISEL)
RS6000_CPU ("e5500", PROCESSOR_PPCE5500,
            MASK_POWERPC64 | MASK_PPC_GFXOPT | MASK_ISEL)
RS6000_CPU ("e6500", PROCESSOR_PPCE6500, POWERPC_7400_MASK | MASK_POWERPC64
            | MASK_MFCRF | MASK_ISEL)


So perhaps we should consider MASK_ISEL as power9 thing only for flags which
include power7-ish or later ISAs?
--- rs6000.c.jj4        2021-04-09 10:18:15.582266372 +0200
+++ rs6000.c    2021-04-19 16:30:07.033208577 +0200
@@ -5766,6 +5766,9 @@ rs6000_machine_from_flags (void)

   /* Disable the flags that should never influence the .machine selection.  */
   flags &= ~(OPTION_MASK_PPC_GFXOPT | OPTION_MASK_PPC_GPOPT);
+  if ((flags & (ISA_3_1_MASKS_SERVER
+               & ~(ISA_2_5_MASKS_SERVER | MASK_ISEL))) == 0)
+    flags &= ~MASK_ISEL;

   if ((flags & (ISA_3_1_MASKS_SERVER & ~ISA_3_0_MASKS_SERVER)) != 0)
     return "power10";