[gcc r13-102] arm: Restrict support of vectors of boolean immediates (PR target/104662)

[Christophe Lyon <clyon@gcc.gnu.org>]

https://gcc.gnu.org/g:e2285af309000b74da0f7dc756a0b55e5f0b1b56

commit r13-102-ge2285af309000b74da0f7dc756a0b55e5f0b1b56
Author: Christophe Lyon <christophe.lyon@arm.com>
Date:   Tue Apr 19 17:34:04 2022 +0200

    arm: Restrict support of vectors of boolean immediates (PR target/104662)
    
    This simple patch avoids the ICE described in the PR:
    internal compiler error: in simd_valid_immediate, at config/arm/arm.cc:12866
    
    with an early exit from simd_valid_immediate if we are trying to
    handle a vector of booleans and MVE is not enabled.
    
    We still get an ICE when compiling the existing
    gcc.dg/rtl/arm/mve-vxbi.c without -march=armv8.1-m.main+mve:
    
    error: unrecognizable insn:
    (insn 7 5 8 2 (set (reg:V4BI 114)
            (const_vector:V4BI [
                    (const_int 1 [0x1])
                    (const_int 0 [0]) repeated x2
                    (const_int 1 [0x1])
                ])) -1
         (nil))
    during RTL pass: ira
    
    but there's little we can do since the testcase explicitly creates
    vectors of booleans which do need MVE.
    
    That is the reason why I do not add a testcase.
    
    2022-04-19  Christophe Lyon  <christophe.lyon@arm.com>
    
            PR target/104662
            * config/arm/arm.cc (simd_valid_immediate): Exit when input is a
            vector of booleans and MVE is not enabled.

Diff:
---
 gcc/config/arm/arm.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gcc/config/arm/arm.cc b/gcc/config/arm/arm.cc
index 14e2fdfeafa..69a18c2f157 100644
--- a/gcc/config/arm/arm.cc
+++ b/gcc/config/arm/arm.cc
@@ -12849,6 +12849,9 @@ simd_valid_immediate (rtx op, machine_mode mode, int inverse,
 	  || n_elts * innersize != 16))
     return -1;
 
+  if (!TARGET_HAVE_MVE && GET_MODE_CLASS (mode) == MODE_VECTOR_BOOL)
+    return -1;
+
   /* Vectors of float constants.  */
   if (GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
     {