[gcc r12-6721] powerc: Fix asm machine directive for some CPUs

[Sebastian Huber]

https://gcc.gnu.org/g:1ead972cef7622682c5e6c4fa563c4a894d6e0c3

commit r12-6721-g1ead972cef7622682c5e6c4fa563c4a894d6e0c3
Author: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date:   Tue Jan 18 12:44:53 2022 +0100

    powerc: Fix asm machine directive for some CPUs
    
    For some CPUs, the assembler machine directive cannot be determined by ISA
    flags.
    
    gcc/
    
            PR target/104090
            * config/rs6000/rs6000.cc (rs6000_machine_from_flags): Use also
            rs6000_cpu.

Diff:
---
 gcc/config/rs6000/rs6000.cc | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 7a4ef5e6c0a..2a338a222c1 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -5935,6 +5935,31 @@ const char *rs6000_machine;
 const char *
 rs6000_machine_from_flags (void)
 {
+  /* For some CPUs, the machine cannot be determined by ISA flags.  We have to
+     check them first.  */
+  switch (rs6000_cpu)
+    {
+    case PROCESSOR_PPC8540:
+    case PROCESSOR_PPC8548:
+      return "e500";
+
+    case PROCESSOR_PPCE300C2:
+    case PROCESSOR_PPCE300C3:
+      return "e300";
+
+    case PROCESSOR_PPCE500MC:
+      return "e500mc";
+
+    case PROCESSOR_PPCE500MC64:
+      return "e500mc64";
+
+    case PROCESSOR_PPCE5500:
+      return "e5500";
+
+    case PROCESSOR_PPCE6500:
+      return "e6500";
+    }
+
   HOST_WIDE_INT flags = rs6000_isa_flags;
 
   /* Disable the flags that should never influence the .machine selection.  */