tcg: Optionally sign-extend 32-bit arguments for 64-bit hosts.

Some hosts (amd64, ia64) have an ABI that ignores the high bits
of the 64-bit register when passing 32-bit arguments.  Others
require the value to be properly sign-extended for the type.
I.e. "int32_t" must be sign-extended and "uint32_t" must be
zero-extended to 64-bits.

To effect this, extend the "sizemask" parameter to tcg_gen_callN
to include the signedness of the type of each parameter.  If the
tcg target requires it, extend each 32-bit argument into a 64-bit
temp and pass that to the function call.

This ABI feature is required by sparc64, ppc64 and s390x.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

1 files changed, 35 insertions, 6 deletions

diff --git a/tcg/tcg.c b/tcg/tcg.c
index 3a18b76c8e..e0a90302a7 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -560,6 +560,24 @@ void tcg_gen_callN(TCGContext *s, TCGv_ptr func, unsigned int flags,
     int real_args;
     int nb_rets;
     TCGArg *nparam;
+
+#if defined(TCG_TARGET_EXTEND_ARGS) && TCG_TARGET_REG_BITS == 64
+    for (i = 0; i < nargs; ++i) {
+        int is_64bit = sizemask & (1 << (i+1)*2);
+        int is_signed = sizemask & (2 << (i+1)*2);
+        if (!is_64bit) {
+            TCGv_i64 temp = tcg_temp_new_i64();
+            TCGv_i64 orig = MAKE_TCGV_I64(args[i]);
+            if (is_signed) {
+                tcg_gen_ext32s_i64(temp, orig);
+            } else {
+                tcg_gen_ext32u_i64(temp, orig);
+            }
+            args[i] = GET_TCGV_I64(temp);
+        }
+    }
+#endif /* TCG_TARGET_EXTEND_ARGS */
+
     *gen_opc_ptr++ = INDEX_op_call;
     nparam = gen_opparam_ptr++;
 #ifdef TCG_TARGET_I386
@@ -588,7 +606,8 @@ void tcg_gen_callN(TCGContext *s, TCGv_ptr func, unsigned int flags,
     real_args = 0;
     for (i = 0; i < nargs; i++) {
 #if TCG_TARGET_REG_BITS < 64
-        if (sizemask & (2 << i)) {
+        int is_64bit = sizemask & (1 << (i+1)*2);
+        if (is_64bit) {
 #ifdef TCG_TARGET_I386
             /* REGPARM case: if the third parameter is 64 bit, it is
                allocated on the stack */
@@ -622,12 +641,12 @@ void tcg_gen_callN(TCGContext *s, TCGv_ptr func, unsigned int flags,
             *gen_opparam_ptr++ = args[i] + 1;
 #endif
             real_args += 2;
-        } else
-#endif
-        {
-            *gen_opparam_ptr++ = args[i];
-            real_args++;
+            continue;
         }
+#endif /* TCG_TARGET_REG_BITS < 64 */
+
+        *gen_opparam_ptr++ = args[i];
+        real_args++;
     }
     *gen_opparam_ptr++ = GET_TCGV_PTR(func);
 
@@ -637,6 +656,16 @@ void tcg_gen_callN(TCGContext *s, TCGv_ptr func, unsigned int flags,
 
     /* total parameters, needed to go backward in the instruction stream */
     *gen_opparam_ptr++ = 1 + nb_rets + real_args + 3;
+
+#if defined(TCG_TARGET_EXTEND_ARGS) && TCG_TARGET_REG_BITS == 64
+    for (i = 0; i < nargs; ++i) {
+        int is_64bit = sizemask & (1 << (i+1)*2);
+        if (!is_64bit) {
+            TCGv_i64 temp = MAKE_TCGV_I64(args[i]);
+            tcg_temp_free_i64(temp);
+        }
+    }
+#endif /* TCG_TARGET_EXTEND_ARGS */
 }
 
 #if TCG_TARGET_REG_BITS == 32