[gcc r14-1620] riscv: Fix insn cost calculation

[gcc r14-1620] riscv: Fix insn cost calculation

[Dimitar Dimitrov]

https://gcc.gnu.org/g:ae6c2d1edf289a8a04557e8fbfd4a61841c53345

commit r14-1620-gae6c2d1edf289a8a04557e8fbfd4a61841c53345
Author: Dimitar Dimitrov <dimitar@dinux.eu>
Date:   Mon Jun 5 21:30:35 2023 +0300

    riscv: Fix insn cost calculation
    
    When building riscv32-none-elf with "--enable-checking=yes,rtl", the
    following ICE is observed:
    
      cc1: internal compiler error: RTL check: expected code 'const_int', have 'const_double' in riscv_const_insns, at config/riscv/riscv.cc:1313
      0x843c4d rtl_check_failed_code1(rtx_def const*, rtx_code, char const*, int, char const*)
              /mnt/nvme/dinux/local-workspace/gcc/gcc/rtl.cc:916
      0x8eab61 riscv_const_insns(rtx_def*)
              /mnt/nvme/dinux/local-workspace/gcc/gcc/config/riscv/riscv.cc:1313
      0x15443bb riscv_legitimate_constant_p
              /mnt/nvme/dinux/local-workspace/gcc/gcc/config/riscv/riscv.cc:826
      0xdd3c71 emit_move_insn(rtx_def*, rtx_def*)
              /mnt/nvme/dinux/local-workspace/gcc/gcc/expr.cc:4310
      0x15f28e5 run_const_vector_selftests
              /mnt/nvme/dinux/local-workspace/gcc/gcc/config/riscv/riscv-selftests.cc:285
      0x15f37bd selftest::riscv_run_selftests()
              /mnt/nvme/dinux/local-workspace/gcc/gcc/config/riscv/riscv-selftests.cc:364
      0x1f6fba9 selftest::run_tests()
              /mnt/nvme/dinux/local-workspace/gcc/gcc/selftest-run-tests.cc:111
      0x11d1f39 toplev::run_self_tests()
              /mnt/nvme/dinux/local-workspace/gcc/gcc/toplev.cc:2185
    
    Fix by following the spirit of the adjacent comment, and using the
    dedicated riscv_const_insns() function to calculate cost for loading a
    constant element.  Infinite recursion is not possible because the first
    invocation is on a CONST_VECTOR, whereas the second is on a single
    element of the vector (e.g. CONST_INT or CONST_DOUBLE).
    
    Regression tested for riscv32-none-elf. No changes in gcc.sum and
    g++.sum.
    
    gcc/ChangeLog:
    
            * config/riscv/riscv.cc (riscv_const_insns): Recursively call
            for constant element of a vector.
    
    Signed-off-by: Dimitar Dimitrov <dimitar@dinux.eu>

Diff:
---
 gcc/config/riscv/riscv.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 21e7d3b3caa..4ff3758434c 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -1310,7 +1310,7 @@ riscv_const_insns (rtx x)
 		   a general-purpose register.  This means we need as many
 		   insns as it takes to load the constant into the GPR
 		   and one vmv.v.x.  */
-		return 1 + riscv_integer_cost (INTVAL (elt));
+		return 1 + riscv_const_insns (elt);
 	      }
 	  }