tcg: Introduce tcg_target_call_oarg_reg

Replace the flat array tcg_target_call_oarg_regs[] with
a function call including the TCGCallReturnKind.

Extend the set of registers for ARM to r0-r3 to match the ABI:
https://github.com/ARM-software/abi-aa/blob/main/aapcs32/aapcs32.rst#result-return

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 123cde7000..a77483eee8 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -151,6 +151,7 @@ static bool tcg_out_sti(TCGContext *s, TCGType type, TCGArg val,
                         TCGReg base, intptr_t ofs);
 static void tcg_out_call(TCGContext *s, const tcg_insn_unit *target,
                          const TCGHelperInfo *info);
+static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot);
 static bool tcg_target_const_match(int64_t val, TCGType type, int ct);
 #ifdef TCG_TARGET_NEED_LDST_LABELS
 static int tcg_out_ldst_finalize(TCGContext *s);
@@ -740,14 +741,16 @@ static void init_call_layout(TCGHelperInfo *info)
     case dh_typecode_s64:
         info->nr_out = 64 / TCG_TARGET_REG_BITS;
         info->out_kind = TCG_CALL_RET_NORMAL;
-        assert(info->nr_out <= ARRAY_SIZE(tcg_target_call_oarg_regs));
+        /* Query the last register now to trigger any assert early. */
+        tcg_target_call_oarg_reg(info->out_kind, info->nr_out - 1);
         break;
     case dh_typecode_i128:
         info->nr_out = 128 / TCG_TARGET_REG_BITS;
         info->out_kind = TCG_CALL_RET_NORMAL; /* TODO */
         switch (/* TODO */ TCG_CALL_RET_NORMAL) {
         case TCG_CALL_RET_NORMAL:
-            assert(info->nr_out <= ARRAY_SIZE(tcg_target_call_oarg_regs));
+            /* Query the last register now to trigger any assert early. */
+            tcg_target_call_oarg_reg(info->out_kind, info->nr_out - 1);
             break;
         case TCG_CALL_RET_BY_REF:
             /*
@@ -4592,7 +4595,7 @@ static void tcg_reg_alloc_call(TCGContext *s, TCGOp *op)
     case TCG_CALL_RET_NORMAL:
         for (i = 0; i < nb_oargs; i++) {
             TCGTemp *ts = arg_temp(op->args[i]);
-            TCGReg reg = tcg_target_call_oarg_regs[i];
+            TCGReg reg = tcg_target_call_oarg_reg(TCG_CALL_RET_NORMAL, i);
 
             /* ENV should not be modified.  */
             tcg_debug_assert(!temp_readonly(ts));