When passing 0xff as an unsigned char function argument, the C frontend
promotion will promote it to int:
<integer_cst 0x7fffe6aa23a8 type <integer_type 0x7fffe98225e8 int> constant 255>
and expand_normal always returns the rtx value using the sign-extended
representation,
(const_int 255 [0xff])
If the C frontend doesn't promote unsigned char to int, expand_normal will
get
<integer_cst 0x7fffe9824018 type <integer_type 0x7fffe9822348 unsigned char > co
nstant 255>
and return
gnu-tgl-3:pts/6[168]> head -50
/tmp/0001-i386-Add-ix86_expand_integer_cst_argument.patch
>From d9dddaad6254cca11b0a55c18291180d6d8d7524 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.to...@gmail.com>
Date: Tue, 12 Nov 2024 09:03:31 +0800
Subject: [PATCH] i386: Add ix86_expand_integer_cst_argument
When passing 0xff as an unsigned char function argument, the C frontend
promotion will promote it to int:
<integer_cst 0x7fffe6aa23a8 type <integer_type 0x7fffe98225e8 int> constant 255>
and expand_normal always returns the rtx value using the sign-extended
representation,
(const_int 255 [0xff])
If the C frontend doesn't promote unsigned char to int, expand_normal will
get
<integer_cst 0x7fffe9824018 type <integer_type 0x7fffe9822348 unsigned char > co
nstant 255>
and return
(const_int -1 [0xffffffffffffffff])
Add ix86_expand_integer_cst_argument to expand the argument before calling
fixup_modeless_constant to extract the 8-bit/16-bit integer constants to
always return
(const_int 255 [0xff])
in this case.
PR middle-end/14907
* config/i386/i386-expand.cc (ix86_expand_integer_cst_argument):
New function.
(ix86_expand_args_builtin): Call ix86_expand_integer_cst_argument
to expand the argument before calling fixup_modeless_constant.
(ix86_expand_round_builtin): Likewise.
(ix86_expand_special_args_builtin): Likewise.
(ix86_expand_builtin): Likewise.
--
H.J.
From d9dddaad6254cca11b0a55c18291180d6d8d7524 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.to...@gmail.com>
Date: Tue, 12 Nov 2024 09:03:31 +0800
Subject: [PATCH] i386: Add ix86_expand_integer_cst_argument
When passing 0xff as an unsigned char function argument, the C frontend
promotion will promote it to int:
<integer_cst 0x7fffe6aa23a8 type <integer_type 0x7fffe98225e8 int> constant 255>
and expand_normal always returns the rtx value using the sign-extended
representation,
(const_int 255 [0xff])
If the C frontend doesn't promote unsigned char to int, expand_normal will
get
<integer_cst 0x7fffe9824018 type <integer_type 0x7fffe9822348 unsigned char > co
nstant 255>
and return
(const_int -1 [0xffffffffffffffff])
Add ix86_expand_integer_cst_argument to expand the argument before calling
fixup_modeless_constant to extract the 8-bit/16-bit integer constants to
always return
(const_int 255 [0xff])
in this case.
PR middle-end/14907
* config/i386/i386-expand.cc (ix86_expand_integer_cst_argument):
New function.
(ix86_expand_args_builtin): Call ix86_expand_integer_cst_argument
to expand the argument before calling fixup_modeless_constant.
(ix86_expand_round_builtin): Likewise.
(ix86_expand_special_args_builtin): Likewise.
(ix86_expand_builtin): Likewise.
Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
---
gcc/config/i386/i386-expand.cc | 45 ++++++++++++++++++++++++++++++----
1 file changed, 40 insertions(+), 5 deletions(-)
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 5c4a8e07d62..6b075fa6ee7 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -11243,6 +11243,41 @@ fixup_modeless_constant (rtx x, machine_mode mode)
return x;
}
+/* Expand the outgoing argument ARG. */
+
+static rtx
+ix86_expand_integer_cst_argument (tree arg)
+{
+ /* expand_normal gets
+
+ <integer_cst 0x7fffe9824018 type <integer_type 0x7fffe9822348 unsigned char > constant 255>
+
+ when passing 0xff as an unsigned char function argument. Since
+ expand_normal always returns the rtx value using the sign-extended
+ representation, it returns
+
+ (const_int -1 [0xffffffffffffffff])
+
+ extract the 8-bit/16-bit integer constants to always return
+
+ (const_int 255 [0xff])
+
+ in this case. */
+
+ if (TREE_CODE (arg) == INTEGER_CST)
+ {
+ tree type = TREE_TYPE (arg);
+ if (INTEGRAL_TYPE_P (type)
+ && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))
+ {
+ HOST_WIDE_INT cst = tree_to_shwi (arg);
+ return GEN_INT (cst);
+ }
+ }
+
+ return expand_normal (arg);
+}
+
/* Subroutine of ix86_expand_builtin to take care of insns with
variable number of operands. */
@@ -12135,7 +12170,7 @@ ix86_expand_args_builtin (const struct builtin_description *d,
for (i = 0; i < nargs; i++)
{
tree arg = CALL_EXPR_ARG (exp, i);
- rtx op = expand_normal (arg);
+ rtx op = ix86_expand_integer_cst_argument (arg);
machine_mode mode = insn_p->operand[i + 1].mode;
/* Need to fixup modeless constant before testing predicate. */
op = fixup_modeless_constant (op, mode);
@@ -12870,7 +12905,7 @@ ix86_expand_round_builtin (const struct builtin_description *d,
for (i = 0; i < nargs; i++)
{
tree arg = CALL_EXPR_ARG (exp, i);
- rtx op = expand_normal (arg);
+ rtx op = ix86_expand_integer_cst_argument (arg);
machine_mode mode = insn_p->operand[i + 1].mode;
bool match = insn_p->operand[i + 1].predicate (op, mode);
@@ -13355,7 +13390,7 @@ ix86_expand_special_args_builtin (const struct builtin_description *d,
machine_mode mode = insn_p->operand[i + 1].mode;
arg = CALL_EXPR_ARG (exp, i + arg_adjust);
- op = expand_normal (arg);
+ op = ix86_expand_integer_cst_argument (arg);
if (i == memory)
{
@@ -15485,7 +15520,7 @@ rdseed_step:
op0 = expand_normal (arg0);
op1 = expand_normal (arg1);
op2 = expand_normal (arg2);
- op3 = expand_normal (arg3);
+ op3 = ix86_expand_integer_cst_argument (arg3);
op4 = expand_normal (arg4);
/* Note the arg order is different from the operand order. */
mode0 = insn_data[icode].operand[1].mode;
@@ -15700,7 +15735,7 @@ rdseed_step:
arg3 = CALL_EXPR_ARG (exp, 3);
arg4 = CALL_EXPR_ARG (exp, 4);
op0 = expand_normal (arg0);
- op1 = expand_normal (arg1);
+ op1 = ix86_expand_integer_cst_argument (arg1);
op2 = expand_normal (arg2);
op3 = expand_normal (arg3);
op4 = expand_normal (arg4);
--
2.47.0
