[gcc r13-2623] xtensa: gcc: fix builtin_apply return value

[gcc r13-2623] xtensa: gcc: fix builtin_apply return value

[Max Filippov]

https://gcc.gnu.org/g:71cd6a0430ca2a2c44e3cf4cc9f3c96d3aef1ab7

commit r13-2623-g71cd6a0430ca2a2c44e3cf4cc9f3c96d3aef1ab7
Author: Max Filippov <jcmvbkbc@gmail.com>
Date:   Sat Sep 10 17:31:07 2022 -0700

    xtensa: gcc: fix builtin_apply return value
    
    xtensa may use up to 4 registers to return a value from a function, but
    recognition of only one register in the xtensa_function_value_regno_p
    and missing untyped_call pattern result in that only one register is
    saved by the __builtin_apply and returned by the __builtin_apply_return.
    
    gcc/
            * config/xtensa/xtensa.cc (xtensa_function_value_regno_p):
            Recognize all 4 return registers.
            * config/xtensa/xtensa.h (GP_RETURN_REG_COUNT): New definition.
            * config/xtensa/xtensa.md (untyped_call): New pattern.

Diff:
---
 gcc/config/xtensa/xtensa.cc |  2 +-
 gcc/config/xtensa/xtensa.h  |  1 +
 gcc/config/xtensa/xtensa.md | 21 +++++++++++++++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/gcc/config/xtensa/xtensa.cc b/gcc/config/xtensa/xtensa.cc
index ac52c015a94..f1b3331ea55 100644
--- a/gcc/config/xtensa/xtensa.cc
+++ b/gcc/config/xtensa/xtensa.cc
@@ -4472,7 +4472,7 @@ xtensa_libcall_value (machine_mode mode, const_rtx fun ATTRIBUTE_UNUSED)
 static bool
 xtensa_function_value_regno_p (const unsigned int regno)
 {
-  return (regno == GP_RETURN);
+  return (regno >= GP_RETURN && regno < GP_RETURN + GP_RETURN_REG_COUNT);
 }
 
 /* The static chain is passed in memory.  Provide rtx giving 'mem'
diff --git a/gcc/config/xtensa/xtensa.h b/gcc/config/xtensa/xtensa.h
index 0f3006d7af8..16e3d55e896 100644
--- a/gcc/config/xtensa/xtensa.h
+++ b/gcc/config/xtensa/xtensa.h
@@ -488,6 +488,7 @@ enum reg_class
    point, and values of coprocessor and user-defined modes.  */
 #define GP_RETURN (GP_REG_FIRST + 2 + WINDOW_SIZE)
 #define GP_OUTGOING_RETURN (GP_REG_FIRST + 2)
+#define GP_RETURN_REG_COUNT 4
 
 /* Symbolic macros for the first/last argument registers.  */
 #define GP_ARG_FIRST (GP_REG_FIRST + 2)
diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md
index f722ea56289..608110c20bc 100644
--- a/gcc/config/xtensa/xtensa.md
+++ b/gcc/config/xtensa/xtensa.md
@@ -2305,6 +2305,27 @@
    (set_attr "mode"	"none")
    (set_attr "length"	"3")])
 
+(define_expand "untyped_call"
+  [(parallel [(call (match_operand 0 "")
+		    (const_int 0))
+	      (match_operand 1 "")
+	      (match_operand 2 "")])]
+  ""
+{
+  int i;
+
+  emit_call_insn (gen_call (operands[0], const0_rtx));
+
+  for (i = 0; i < XVECLEN (operands[2], 0); i++)
+    {
+      rtx set = XVECEXP (operands[2], 0, i);
+      emit_move_insn (SET_DEST (set), SET_SRC (set));
+    }
+
+  emit_insn (gen_blockage ());
+  DONE;
+})
+
 (define_insn "entry"
   [(set (reg:SI A1_REG)
 	(unspec_volatile:SI [(match_operand:SI 0 "const_int_operand" "i")]