Op 24-06-2025 om 22:18 schreef Herman ten Brugge:
The recent change to atomic functions has some problems.
I fixed one. See
https://repo.or.cz/tinycc.git/commitdiff/32b597746c1c9da4656ef34e2930c604f6c13c81
Another problem is the arm code. It uses tumb code. But this should be
armv6k.
The old code had:
#ifndef __TINYC__
.arch armv6k
.syntax unified
#endif
The new code is:
.thumb
.syntax unified
tcc does not support .thumb or .syntax unified.
If I disassemble the tcc code for atomic_flag_clear I get:
00022a34 <atomic_flag_clear>:
22a34: f3bf2300 vsubw.u<illegal width 64> q1,
<illegal reg q7.5>, d0
22a38: f3bf7003 vaddl.u<illegal width 64>
<illegal reg q3.5>, d15, d3
22a3c: Address 0x22a3c is out of bounds.
Also the windows code does not work. The endbr32 is not supported.
If I remove this the testcase 125_atomic_misc and testcase
136_atomic_gcc_style fail for i386.
I debugged the windows code some more and found that it was x86_64
failing instead of i386.
The problems is that windows uses a different calling convention. See
arg_regs in x86_64-gen.c.
I implemented the endbr32 in tcc. See attachment.
So arm code should use armv6k instead of thumb and x86_64 should use
different calling
convention for windows.
Herman
Herman
diff --git a/i386-asm.c b/i386-asm.c
index 470b20e..022d4ab 100644
--- a/i386-asm.c
+++ b/i386-asm.c
@@ -1016,6 +1016,16 @@ again:
tcc_error("bad MODR/M opcode without operands");
goto modrm_found;
}
+#else
+ if (!nb_ops) {
+ i = 0;
+ ops[i].type = OP_REG;
+ if (pa->sym == TOK_ASM_endbr32)
+ ops[i].reg = 3; // bx
+ else
+ tcc_error("bad MODR/M opcode without operands");
+ goto modrm_found;
+ }
#endif
/* first look for an ea operand */
for(i = 0;i < nb_ops; i++) {
diff --git a/i386-asm.h b/i386-asm.h
index 0f99b28..107fd3d 100644
--- a/i386-asm.h
+++ b/i386-asm.h
@@ -37,7 +37,10 @@
DEF_ASM_OP0(pause, 0xf390)
DEF_ASM_OP0(xlat, 0xd7)
- /* strings */
+ /* Control-Flow Enforcement */
+ DEF_ASM_OP0L(endbr32, 0xf30f1e, 7, OPC_MODRM)
+
+ /* strings */
ALT(DEF_ASM_OP0L(cmpsb, 0xa6, 0, OPC_BWLX))
ALT(DEF_ASM_OP0L(scmpb, 0xa6, 0, OPC_BWLX))
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