[gcc(refs/vendors/ARM/heads/morello)] aarch64: Fix ICE on fpsr fpcr getters [PR96968]

[Matthew Malcomson <matmal01@gcc.gnu.org>]

https://gcc.gnu.org/g:035f12ba83a93e628e1863dbc105f6877c6a86a4

commit 035f12ba83a93e628e1863dbc105f6877c6a86a4
Author: Andrea Corallo <andrea.corallo@arm.com>
Date:   Mon Sep 14 14:47:24 2020 +0100

    aarch64: Fix ICE on fpsr fpcr getters [PR96968]
    
    Backported from f5e73de00e9 on the GCC master branch.
    
    gcc/ChangeLog
    
    2020-09-14  Andrea Corallo  <andrea.corallo@arm.com>
    
            PR target/96968
            * config/aarch64/aarch64-builtins.c
            (aarch64_expand_fpsr_fpcr_setter): Fix comment nit.
            (aarch64_expand_fpsr_fpcr_getter): New function, expand these
            getters using expand_insn machinery.
            (aarch64_general_expand_builtin): Make use of.
    
    gcc/testsuite/ChangeLog
    
    2020-09-14  Andrea Corallo  <andrea.corallo@arm.com>
    
            PR target/96968
            * gcc.target/aarch64/pr96968.c: New test.

Diff:
---
 gcc/config/aarch64/aarch64-builtins.c      | 30 +++++++++++++++++++++---------
 gcc/testsuite/gcc.target/aarch64/pr96968.c | 28 ++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/gcc/config/aarch64/aarch64-builtins.c b/gcc/config/aarch64/aarch64-builtins.c
index 1e1a17ad003..61afc1d9630 100644
--- a/gcc/config/aarch64/aarch64-builtins.c
+++ b/gcc/config/aarch64/aarch64-builtins.c
@@ -2031,7 +2031,7 @@ aarch64_expand_builtin_memtag (int fcode, tree exp, rtx target)
   return target;
 }
 
-/* Expand an expression EXP as fpsr or cpsr setter (depending on
+/* Expand an expression EXP as fpsr or fpcr setter (depending on
    UNSPEC) using MODE.  */
 static void
 aarch64_expand_fpsr_fpcr_setter (int unspec, machine_mode mode, tree exp)
@@ -2041,6 +2041,18 @@ aarch64_expand_fpsr_fpcr_setter (int unspec, machine_mode mode, tree exp)
   emit_insn (gen_aarch64_set (unspec, mode, op));
 }
 
+/* Expand a fpsr or fpcr getter (depending on UNSPEC) using MODE.
+   Return the target.  */
+static rtx
+aarch64_expand_fpsr_fpcr_getter (enum insn_code icode, machine_mode mode,
+				 rtx target)
+{
+  expand_operand op;
+  create_output_operand (&op, target, mode);
+  expand_insn (icode, 1, &op);
+  return op.value;
+}
+
 /* Expand an expression EXP that calls built-in function FCODE,
    with result going to TARGET if that's convenient.  IGNORE is true
    if the result of the builtin is ignored.  */
@@ -2055,26 +2067,26 @@ aarch64_general_expand_builtin (unsigned int fcode, tree exp, rtx target,
   switch (fcode)
     {
     case AARCH64_BUILTIN_GET_FPCR:
-      emit_insn (gen_aarch64_get (UNSPECV_GET_FPCR, SImode, target));
-      return target;
+      return aarch64_expand_fpsr_fpcr_getter (CODE_FOR_aarch64_get_fpcrsi,
+					      SImode, target);
     case AARCH64_BUILTIN_SET_FPCR:
       aarch64_expand_fpsr_fpcr_setter (UNSPECV_SET_FPCR, SImode, exp);
       return target;
     case AARCH64_BUILTIN_GET_FPSR:
-      emit_insn (gen_aarch64_get (UNSPECV_GET_FPSR, SImode, target));
-      return target;
+      return aarch64_expand_fpsr_fpcr_getter (CODE_FOR_aarch64_get_fpsrsi,
+					      SImode, target);
     case AARCH64_BUILTIN_SET_FPSR:
       aarch64_expand_fpsr_fpcr_setter (UNSPECV_SET_FPSR, SImode, exp);
       return target;
     case AARCH64_BUILTIN_GET_FPCR64:
-      emit_insn (gen_aarch64_get (UNSPECV_GET_FPCR, DImode, target));
-      return target;
+      return aarch64_expand_fpsr_fpcr_getter (CODE_FOR_aarch64_get_fpcrdi,
+					      DImode, target);
     case AARCH64_BUILTIN_SET_FPCR64:
       aarch64_expand_fpsr_fpcr_setter (UNSPECV_SET_FPCR, DImode, exp);
       return target;
     case AARCH64_BUILTIN_GET_FPSR64:
-      emit_insn (gen_aarch64_get (UNSPECV_GET_FPSR, DImode, target));
-      return target;
+      return aarch64_expand_fpsr_fpcr_getter (CODE_FOR_aarch64_get_fpsrdi,
+					      DImode, target);
     case AARCH64_BUILTIN_SET_FPSR64:
       aarch64_expand_fpsr_fpcr_setter (UNSPECV_SET_FPSR, DImode, exp);
       return target;
diff --git a/gcc/testsuite/gcc.target/aarch64/pr96968.c b/gcc/testsuite/gcc.target/aarch64/pr96968.c
new file mode 100644
index 00000000000..21ffd955153
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr96968.c
@@ -0,0 +1,28 @@
+/* { dg-options "-O1" } */
+
+void
+fpsr_getter (void)
+{
+  unsigned int fpsr = __builtin_aarch64_get_fpsr ();
+}
+
+void
+fpsr64_getter (void)
+{
+  unsigned long fpsr = __builtin_aarch64_get_fpsr64 ();
+}
+
+void
+fpcr_getter (void)
+{
+  unsigned int fpcr = __builtin_aarch64_get_fpcr ();
+}
+
+void
+fpcr64_getter (void)
+{
+  unsigned long fpcr = __builtin_aarch64_get_fpcr64 ();
+}
+
+/* { dg-final { scan-assembler-times {\tmrs\tx0, fpsr\n} 2 } } */
+/* { dg-final { scan-assembler-times {\tmrs\tx0, fpcr\n} 2 } } */