Re: [PATCH] arm: Restrict support of vectors of boolean immediates (PR target/104662)

[Christophe Lyon via Gcc-patches]

ping?

On 4/20/22 10:50, Christophe Lyon wrote:

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.l...@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.
---
  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)
      {