[gcc r14-8397] aarch64: Fix __builtin_apply with -mgeneral-regs-only [PR113486]

[Andrew Pinski <pinskia@gcc.gnu.org>]

https://gcc.gnu.org/g:d3ff08a3764f2047d02b35212fc4f1da9eb75c7b

commit r14-8397-gd3ff08a3764f2047d02b35212fc4f1da9eb75c7b
Author: Andrew Pinski <quic_apinski@quicinc.com>
Date:   Thu Jan 18 10:40:04 2024 -0800

    aarch64: Fix __builtin_apply with -mgeneral-regs-only [PR113486]
    
    The problem here is the builtin apply mechanism thinks the FP registers
    are to be used due to get_raw_arg_mode not returning VOIDmode. This
    fixes that oversight and the backend now returns VOIDmode for non-general-regs
    if TARGET_GENERAL_REGS_ONLY is true.
    
    Built and tested for aarch64-linux-gnu with no regressions.
    
            PR target/113486
    
    gcc/ChangeLog:
    
            * config/aarch64/aarch64.cc (aarch64_get_reg_raw_mode): For
            TARGET_GENERAL_REGS_ONLY, return VOIDmode for non-GP_REGNUM_P regno.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/aarch64/builtin_apply-1.c: New test.
    
    Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>

Diff:
---
 gcc/config/aarch64/aarch64.cc                      |  4 ++++
 gcc/testsuite/gcc.target/aarch64/builtin_apply-1.c | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index c54b6067949..3d6dd98c5c5 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -7221,6 +7221,10 @@ aarch64_function_arg_boundary (machine_mode mode, const_tree type)
 static fixed_size_mode
 aarch64_get_reg_raw_mode (int regno)
 {
+  /* Don't use any non GP registers for __builtin_apply and
+     __builtin_return if general registers only mode is requested. */
+  if (TARGET_GENERAL_REGS_ONLY && !GP_REGNUM_P (regno))
+    return as_a <fixed_size_mode> (VOIDmode);
   if (TARGET_SVE && FP_REGNUM_P (regno))
     /* Don't use the SVE part of the register for __builtin_apply and
        __builtin_return.  The SVE registers aren't used by the normal PCS,
diff --git a/gcc/testsuite/gcc.target/aarch64/builtin_apply-1.c b/gcc/testsuite/gcc.target/aarch64/builtin_apply-1.c
new file mode 100644
index 00000000000..d70abe037d2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/builtin_apply-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-mgeneral-regs-only" } */
+/* PR target/113486 */
+
+
+/* __builtin_apply should not use FP registers if 
+   general registers only mode is requested. */
+void
+foo (void)
+{
+  __builtin_apply (foo, 0, 0);
+}