[committed][RISC-V] Fix recent rvv/base/spill testcase failures

[Jeff Law]

As Jaiwei noted, many (all?) of the rvv/base/spill tests started failing 
after the introduction of shrink-wrapping.

The core issue is we're expecting the frame to have a constant size, but 
it doesn't.  So when using the to_constant method we abort.


The safest thing to do is to set no shrink-wrapping components when the 
frame size is not fixed.  We might be able to do better later -- iff we 
know the offset to the GPRs/FPRs is fixed and fits into the appropriate 
number of bits.


Bootstrapped and regression tested (C-only) on riscv64-linux-gnu.  As 
expected, it fixes a bucketload of failures in rvv/base/spill-*.c.


Installed on the trunk,

Jeff
commit ca73d4c80ea06087d9dd22594e5670bb15e21066
Author: Jeff Law <jeffreya...@gmail.com>
Date:   Tue Nov 22 18:12:45 2022 -0500

    Fix recent rvv/base/spill testcase failures
    
    he core issue is we're expecting the frame to have a constant size, but it
    doesn't.  So when using the to_constant method we abort.
    
    The safest thing to do is to set no shrink-wrapping components when the
    frame size is not fixed.  We might be able to do better later -- iff we
    know the offset to the GPRs/FPRs is fixed and fits into the appropriate
    number of bits.
    
    Bootstrapped and regression tested (C-only) on riscv64-linux-gnu.  As
    expected, it fixes a bucketload of failures in rvv/base/spill-*.c.
    
    gcc/
            * config/riscv/riscv.cc (riscv_get_separate_components): Do not
            do shrink-wrapping for a frame with a variable size.

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 7ec4ce97e6c..7bfc0e9f595 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -5340,7 +5340,8 @@ riscv_get_separate_components (void)
   bitmap_clear (components);
 
   if (riscv_use_save_libcall (&cfun->machine->frame)
-      || cfun->machine->interrupt_handler_p)
+      || cfun->machine->interrupt_handler_p
+      || !cfun->machine->frame.gp_sp_offset.is_constant ())
     return components;
 
   offset = cfun->machine->frame.gp_sp_offset.to_constant ();