[gcc(refs/users/clyon/heads/mve-autovec)] arm: Fix constraint check for V8HI in mve_vector_mem_operand

[gcc(refs/users/clyon/heads/mve-autovec)] arm: Fix constraint check for V8HI in mve_vector_mem_operand

[Christophe Lyon]

https://gcc.gnu.org/g:d7876d4fb9cb5e00b19ce40e4af2c6206484abf2

commit d7876d4fb9cb5e00b19ce40e4af2c6206484abf2
Author: Christophe Lyon <christophe.lyon@foss.st.com>
Date:   Wed Dec 8 08:01:07 2021 +0000

    arm: Fix constraint check for V8HI in mve_vector_mem_operand
    
    When compiling gcc.target/arm/mve/intrinsics/mve_immediates_1_n.c with
    -mthumb -mfloat-abi=hard -march=armv8.1-m.main+mve.fp+fp.dp, the compiler
    crashes because:
    error: insn does not satisfy its constraints:
    (insn 28 14 17 2 (set (reg:V8HI 16 s0 [orig:249 u16 ] [249])
        (mem/c:V8HI (pre_modify:SI (reg/f:SI 12 ip [248])
                (plus:SI (reg/f:SI 12 ip [248])
                    (const_int 32 [0x20]))) [1 u16+0 S16 A64])) "arm_mve.h":17113:10 3011 {*mve_movv8hi}
        (expr_list:REG_INC (reg/f:SI 12 ip [248])
          (nil)))
    during RTL pass: reload
    
    We are trying to generate:
    vldrh.16        q3, [ip], #14
    but the constraint check fails because ip is not a low reg.
    
    This patch replaces LAST_LO_REGNUM by LAST_ARM_REGNUM in
    mve_vector_mem_operand and avoids the ICE.
    
    2022-01-13  Christophe Lyon  <christophe.lyon@foss.st.com>
    
            gcc/
            * config/arm/arm.c (mve_vector_mem_operand): Fix handling of V8HI.

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

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 7d56fa71806..5edca248fb7 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -13479,7 +13479,7 @@ mve_vector_mem_operand (machine_mode mode, rtx op, bool strict)
 	  case E_V4HImode:
 	  case E_V4HFmode:
 	    if (val % 2 == 0 && abs (val) <= 254)
-	      return reg_no <= LAST_LO_REGNUM
+	      return reg_no <= LAST_ARM_REGNUM
 		|| reg_no >= FIRST_PSEUDO_REGISTER;
 	    return FALSE;
 	  case E_V4SImode: