std: make all MIPS inline asm safe for MIPS I

MIPS I has load hazards so we need to insert nops in a few places. This is not a
problem for MIPS II and later.

While doing this, I also touched up all the inline asm to use ABI register
aliases and a consistent formatting convention. Also fixed a few places that
didn't properly check if the syscall return value should be negated.
This commit is contained in:
Alex Rønne Petersen 2025-10-18 01:56:20 +02:00
parent f3da54f53c
commit b8d776928a
No known key found for this signature in database
5 changed files with 223 additions and 232 deletions

View file

@ -5,10 +5,10 @@ const SYS = std.os.linux.SYS;
pub fn syscall0(number: SYS) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ subu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ subu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
: .{ .r1 = true, .r3 = true, .r4 = true, .r5 = true, .r6 = true, .r7 = true, .r8 = true, .r9 = true, .r10 = true, .r11 = true, .r12 = true, .r13 = true, .r14 = true, .r15 = true, .r24 = true, .r25 = true, .hi = true, .lo = true, .memory = true });
@ -16,17 +16,15 @@ pub fn syscall0(number: SYS) u32 {
pub fn syscall_pipe(fd: *[2]i32) u32 {
return asm volatile (
\\ .set noat
\\ .set noreorder
\\ syscall
\\ beq $7, $zero, 1f
\\ nop
\\ beq $a3, $zero, 1f
\\ blez $v0, 2f
\\ subu $v0, $zero, $v0
\\ b 2f
\\ subu $2, $0, $2
\\ 1:
\\ sw $2, 0($4)
\\ sw $3, 4($4)
\\ 2:
\\1:
\\ sw $v0, 0($a0)
\\ sw $v1, 4($a0)
\\2:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(SYS.pipe)),
[fd] "{$4}" (fd),
@ -36,10 +34,10 @@ pub fn syscall_pipe(fd: *[2]i32) u32 {
pub fn syscall1(number: SYS, arg1: u32) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ subu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ subu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -49,10 +47,10 @@ pub fn syscall1(number: SYS, arg1: u32) u32 {
pub fn syscall2(number: SYS, arg1: u32, arg2: u32) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ subu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ subu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -63,10 +61,10 @@ pub fn syscall2(number: SYS, arg1: u32, arg2: u32) u32 {
pub fn syscall3(number: SYS, arg1: u32, arg2: u32, arg3: u32) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ subu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ subu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -78,10 +76,10 @@ pub fn syscall3(number: SYS, arg1: u32, arg2: u32, arg3: u32) u32 {
pub fn syscall4(number: SYS, arg1: u32, arg2: u32, arg3: u32, arg4: u32) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ subu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ subu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -91,17 +89,19 @@ pub fn syscall4(number: SYS, arg1: u32, arg2: u32, arg3: u32, arg4: u32) u32 {
: .{ .r1 = true, .r3 = true, .r8 = true, .r9 = true, .r10 = true, .r11 = true, .r12 = true, .r13 = true, .r14 = true, .r15 = true, .r24 = true, .r25 = true, .hi = true, .lo = true, .memory = true });
}
// NOTE: The o32 calling convention requires the callee to reserve 16 bytes for
// the first four arguments even though they're passed in $a0-$a3.
pub fn syscall5(number: SYS, arg1: u32, arg2: u32, arg3: u32, arg4: u32, arg5: u32) u32 {
return asm volatile (
\\ .set noat
\\ subu $sp, $sp, 24
\\ sw %[arg5], 16($sp)
\\ syscall
\\ addu $sp, $sp, 24
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ subu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ subu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -112,9 +112,6 @@ pub fn syscall5(number: SYS, arg1: u32, arg2: u32, arg3: u32, arg4: u32, arg5: u
: .{ .r1 = true, .r3 = true, .r8 = true, .r9 = true, .r10 = true, .r11 = true, .r12 = true, .r13 = true, .r14 = true, .r15 = true, .r24 = true, .r25 = true, .hi = true, .lo = true, .memory = true });
}
// NOTE: The o32 calling convention requires the callee to reserve 16 bytes for
// the first four arguments even though they're passed in $a0-$a3.
pub fn syscall6(
number: SYS,
arg1: u32,
@ -125,16 +122,15 @@ pub fn syscall6(
arg6: u32,
) u32 {
return asm volatile (
\\ .set noat
\\ subu $sp, $sp, 24
\\ sw %[arg5], 16($sp)
\\ sw %[arg6], 20($sp)
\\ syscall
\\ addu $sp, $sp, 24
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ subu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ subu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -157,17 +153,16 @@ pub fn syscall7(
arg7: u32,
) u32 {
return asm volatile (
\\ .set noat
\\ subu $sp, $sp, 32
\\ sw %[arg5], 16($sp)
\\ sw %[arg6], 20($sp)
\\ sw %[arg7], 24($sp)
\\ syscall
\\ addu $sp, $sp, 32
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ subu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ subu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -182,52 +177,51 @@ pub fn syscall7(
pub fn clone() callconv(.naked) u32 {
// __clone(func, stack, flags, arg, ptid, tls, ctid)
// 3, 4, 5, 6, 7, 8, 9
// a0, a1, a2, a3, +0, +4, +8
//
// syscall(SYS_clone, flags, stack, ptid, tls, ctid)
// 2 4, 5, 6, 7, 8
// v0 a0, a1, a2, a3, +0
asm volatile (
\\ # Save function pointer and argument pointer on new thread stack
\\ and $5, $5, -8
\\ subu $5, $5, 16
\\ sw $4, 0($5)
\\ sw $7, 4($5)
\\ # Shuffle (fn,sp,fl,arg,ptid,tls,ctid) to (fl,sp,ptid,tls,ctid)
\\ move $4, $6
\\ lw $6, 16($sp)
\\ lw $7, 20($sp)
\\ lw $9, 24($sp)
\\ subu $sp, $sp, 16
\\ sw $9, 16($sp)
\\ li $2, 4120 # SYS_clone
\\ syscall
\\ beq $7, $0, 1f
\\ nop
\\ addu $sp, $sp, 16
\\ jr $ra
\\ subu $2, $0, $2
\\1:
\\ beq $2, $0, 1f
\\ nop
\\ addu $sp, $sp, 16
\\ jr $ra
\\ nop
\\ # Save function pointer and argument pointer on new thread stack
\\ and $a1, $a1, -8
\\ subu $a1, $a1, 16
\\ sw $a0, 0($a1)
\\ sw $a3, 4($a1)
\\
\\ # Shuffle (fn,sp,fl,arg,ptid,tls,ctid) to (fl,sp,ptid,tls,ctid)
\\ move $a0, $a2
\\ lw $a2, 16($sp)
\\ lw $a3, 20($sp)
\\ lw $t1, 24($sp)
\\ subu $sp, $sp, 16
\\ sw $t1, 16($sp)
\\ li $v0, 4120 # SYS_clone
\\ syscall
\\ beq $a3, $zero, 1f
\\ blez $v0, 2f
\\ subu $v0, $zero, $v0
\\ b 2f
\\1:
\\ beq $v0, $zero, 3f
\\2:
\\ addu $sp, $sp, 16
\\ jr $ra
\\3:
);
if (builtin.unwind_tables != .none or !builtin.strip_debug_info) asm volatile (
\\ .cfi_undefined $ra
\\ .cfi_undefined $ra
);
asm volatile (
\\ move $fp, $zero
\\ move $ra, $zero
\\ move $fp, $zero
\\ move $ra, $zero
\\
\\ lw $25, 0($sp)
\\ lw $4, 4($sp)
\\ jalr $25
\\ nop
\\ move $4, $2
\\ li $2, 4001 # SYS_exit
\\ syscall
\\ lw $t9, 0($sp)
\\ lw $a0, 4($sp)
\\ jalr $t9
\\
\\ move $a0, $v0
\\ li $v0, 4001 # SYS_exit
\\ syscall
);
}

View file

@ -5,10 +5,10 @@ const SYS = std.os.linux.SYS;
pub fn syscall0(number: SYS) u64 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u64),
: [number] "{$2}" (@intFromEnum(number)),
: .{ .r1 = true, .r3 = true, .r4 = true, .r5 = true, .r6 = true, .r7 = true, .r8 = true, .r9 = true, .r10 = true, .r11 = true, .r12 = true, .r13 = true, .r14 = true, .r15 = true, .r24 = true, .r25 = true, .hi = true, .lo = true, .memory = true });
@ -16,17 +16,15 @@ pub fn syscall0(number: SYS) u64 {
pub fn syscall_pipe(fd: *[2]i32) u64 {
return asm volatile (
\\ .set noat
\\ .set noreorder
\\ syscall
\\ beq $7, $zero, 1f
\\ nop
\\ beq $a3, $zero, 1f
\\ blez $v0, 2f
\\ dsubu $v0, $zero, $v0
\\ b 2f
\\ subu $2, $0, $2
\\ 1:
\\ sw $2, 0($4)
\\ sw $3, 4($4)
\\ 2:
\\1:
\\ sw $v0, 0($a0)
\\ sw $v1, 4($a0)
\\2:
: [ret] "={$2}" (-> u64),
: [number] "{$2}" (@intFromEnum(SYS.pipe)),
[fd] "{$4}" (fd),
@ -36,11 +34,10 @@ pub fn syscall_pipe(fd: *[2]i32) u64 {
pub fn syscall1(number: SYS, arg1: u64) u64 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ nop
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u64),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -50,10 +47,10 @@ pub fn syscall1(number: SYS, arg1: u64) u64 {
pub fn syscall2(number: SYS, arg1: u64, arg2: u64) u64 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u64),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -64,10 +61,10 @@ pub fn syscall2(number: SYS, arg1: u64, arg2: u64) u64 {
pub fn syscall3(number: SYS, arg1: u64, arg2: u64, arg3: u64) u64 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u64),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -79,10 +76,10 @@ pub fn syscall3(number: SYS, arg1: u64, arg2: u64, arg3: u64) u64 {
pub fn syscall4(number: SYS, arg1: u64, arg2: u64, arg3: u64, arg4: u64) u64 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u64),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -95,10 +92,10 @@ pub fn syscall4(number: SYS, arg1: u64, arg2: u64, arg3: u64, arg4: u64) u64 {
pub fn syscall5(number: SYS, arg1: u64, arg2: u64, arg3: u64, arg4: u64, arg5: u64) u64 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u64),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -120,10 +117,10 @@ pub fn syscall6(
) u64 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u64),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -147,10 +144,10 @@ pub fn syscall7(
) u64 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u64),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -165,33 +162,33 @@ pub fn syscall7(
pub fn clone() callconv(.naked) u64 {
// __clone(func, stack, flags, arg, ptid, tls, ctid)
// 3, 4, 5, 6, 7, 8, 9
// a0, a1, a2, a3, a4, a5, a6
//
// syscall(SYS_clone, flags, stack, ptid, tls, ctid)
// 2 4, 5, 6, 7, 8
// v0 a0, a1, a2, a3, a4
asm volatile (
\\ # Save function pointer and argument pointer on new thread stack
\\ and $5, $5, -16
\\ dsubu $5, $5, 16
\\ sd $4, 0($5)
\\ sd $7, 8($5)
\\ and $a1, $a1, -16
\\ dsubu $a1, $a1, 16
\\ sd $a0, 0($a1)
\\ sd $a3, 8($a1)
\\
\\ # Shuffle (fn,sp,fl,arg,ptid,tls,ctid) to (fl,sp,ptid,tls,ctid)
\\ move $4, $6
\\ move $6, $8
\\ move $7, $9
\\ move $8, $10
\\ li $2, 5055 # SYS_clone
\\ move $a0, $a2
\\ move $a2, $a4
\\ move $a3, $a5
\\ move $a4, $a6
\\ li $v0, 5055 # SYS_clone
\\ syscall
\\ beq $7, $0, 1f
\\ nop
\\ jr $ra
\\ dsubu $2, $0, $2
\\ beq $a3, $zero, 1f
\\ blez $v0, 2f
\\ dsubu $v0, $zero, $v0
\\ b 2f
\\1:
\\ beq $2, $0, 1f
\\ nop
\\ beq $v0, $zero, 3f
\\2:
\\ jr $ra
\\ nop
\\1:
\\3:
);
if (builtin.unwind_tables != .none or !builtin.strip_debug_info) asm volatile (
\\ .cfi_undefined $ra
@ -200,12 +197,12 @@ pub fn clone() callconv(.naked) u64 {
\\ move $fp, $zero
\\ move $ra, $zero
\\
\\ ld $25, 0($sp)
\\ ld $4, 8($sp)
\\ jalr $25
\\ nop
\\ move $4, $2
\\ li $2, 5058 # SYS_exit
\\ ld $t9, 0($sp)
\\ ld $a0, 8($sp)
\\ jalr $t9
\\
\\ move $a0, $v0
\\ li $v0, 5058 # SYS_exit
\\ syscall
);
}

View file

@ -7,10 +7,10 @@ const SYS = std.os.linux.SYS;
pub fn syscall0(number: SYS) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
: .{ .r1 = true, .r3 = true, .r4 = true, .r5 = true, .r6 = true, .r7 = true, .r8 = true, .r9 = true, .r10 = true, .r11 = true, .r12 = true, .r13 = true, .r14 = true, .r15 = true, .r24 = true, .r25 = true, .hi = true, .lo = true, .memory = true });
@ -18,17 +18,15 @@ pub fn syscall0(number: SYS) u32 {
pub fn syscall_pipe(fd: *[2]i32) u32 {
return asm volatile (
\\ .set noat
\\ .set noreorder
\\ syscall
\\ beq $7, $zero, 1f
\\ nop
\\ beq $a3, $zero, 1f
\\ blez $v0, 2f
\\ dsubu $v0, $zero, $v0
\\ b 2f
\\ subu $2, $0, $2
\\ 1:
\\ sw $2, 0($4)
\\ sw $3, 4($4)
\\ 2:
\\1:
\\ sw $v0, 0($a0)
\\ sw $v1, 4($a0)
\\2:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(SYS.pipe)),
[fd] "{$4}" (fd),
@ -38,11 +36,10 @@ pub fn syscall_pipe(fd: *[2]i32) u32 {
pub fn syscall1(number: SYS, arg1: u32) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ nop
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -52,10 +49,10 @@ pub fn syscall1(number: SYS, arg1: u32) u32 {
pub fn syscall2(number: SYS, arg1: u32, arg2: u32) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -66,10 +63,10 @@ pub fn syscall2(number: SYS, arg1: u32, arg2: u32) u32 {
pub fn syscall3(number: SYS, arg1: u32, arg2: u32, arg3: u32) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -81,10 +78,10 @@ pub fn syscall3(number: SYS, arg1: u32, arg2: u32, arg3: u32) u32 {
pub fn syscall4(number: SYS, arg1: u32, arg2: u32, arg3: u32, arg4: u32) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -97,10 +94,10 @@ pub fn syscall4(number: SYS, arg1: u32, arg2: u32, arg3: u32, arg4: u32) u32 {
pub fn syscall5(number: SYS, arg1: u32, arg2: u32, arg3: u32, arg4: u32, arg5: u32) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -122,10 +119,10 @@ pub fn syscall6(
) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -149,10 +146,10 @@ pub fn syscall7(
) u32 {
return asm volatile (
\\ syscall
\\ beq $7, $zero, 1f
\\ blez $2, 1f
\\ dsubu $2, $0, $2
\\ 1:
\\ beq $a3, $zero, 1f
\\ blez $v0, 1f
\\ dsubu $v0, $zero, $v0
\\1:
: [ret] "={$2}" (-> u32),
: [number] "{$2}" (@intFromEnum(number)),
[arg1] "{$4}" (arg1),
@ -167,33 +164,33 @@ pub fn syscall7(
pub fn clone() callconv(.naked) u32 {
// __clone(func, stack, flags, arg, ptid, tls, ctid)
// 3, 4, 5, 6, 7, 8, 9
// a0, a1, a2, a3, a4, a5, a6
//
// syscall(SYS_clone, flags, stack, ptid, tls, ctid)
// 2 4, 5, 6, 7, 8
// v0 a0, a1, a2, a3, a4
asm volatile (
\\ # Save function pointer and argument pointer on new thread stack
\\ and $5, $5, -16
\\ dsubu $5, $5, 16
\\ sd $4, 0($5)
\\ sd $7, 8($5)
\\ and $a1, $a1, -16
\\ dsubu $a1, $a1, 16
\\ sd $a0, 0($a1)
\\ sd $a3, 8($a1)
\\
\\ # Shuffle (fn,sp,fl,arg,ptid,tls,ctid) to (fl,sp,ptid,tls,ctid)
\\ move $4, $6
\\ move $6, $8
\\ move $7, $9
\\ move $8, $10
\\ li $2, 5055 # SYS_clone
\\ move $a0, $a2
\\ move $a2, $a4
\\ move $a3, $a5
\\ move $a4, $a6
\\ li $v0, 5055 # SYS_clone
\\ syscall
\\ beq $7, $0, 1f
\\ nop
\\ jr $ra
\\ dsubu $2, $0, $2
\\ beq $a3, $zero, 1f
\\ blez $v0, 2f
\\ dsubu $v0, $zero, $v0
\\ b 2f
\\1:
\\ beq $2, $0, 1f
\\ nop
\\ beq $v0, $zero, 3f
\\2:
\\ jr $ra
\\ nop
\\1:
\\3:
);
if (builtin.unwind_tables != .none or !builtin.strip_debug_info) asm volatile (
\\ .cfi_undefined $ra
@ -202,12 +199,12 @@ pub fn clone() callconv(.naked) u32 {
\\ move $fp, $zero
\\ move $ra, $zero
\\
\\ ld $25, 0($sp)
\\ ld $4, 8($sp)
\\ jalr $25
\\ nop
\\ move $4, $2
\\ li $2, 5058 # SYS_exit
\\ ld $t9, 0($sp)
\\ ld $a0, 8($sp)
\\ jalr $t9
\\
\\ move $a0, $v0
\\ li $v0, 5058 # SYS_exit
\\ syscall
);
}

View file

@ -121,8 +121,9 @@ inline fn getDynamicSymbol() [*]const elf.Dyn {
\\ .hidden _DYNAMIC
\\ bal 1f
\\ .gpword _DYNAMIC
\\ 1:
\\1:
\\ lw %[ret], 0($ra)
\\ nop
\\ addu %[ret], %[ret], $gp
: [ret] "=r" (-> [*]const elf.Dyn),
:
@ -133,7 +134,7 @@ inline fn getDynamicSymbol() [*]const elf.Dyn {
\\ .balign 8
\\ bal 1f
\\ .gpdword _DYNAMIC
\\ 1:
\\1:
\\ ld %[ret], 0($ra)
\\ daddu %[ret], %[ret], $gp
: [ret] "=r" (-> [*]const elf.Dyn),

View file

@ -325,24 +325,26 @@ fn _start() callconv(.naked) noreturn {
\\ jsr (%%pc, %%a0)
,
.mips, .mipsel =>
\\ move $fp, $0
\\ move $fp, $zero
\\ bal 1f
\\ .gpword .
\\ .gpword %[posixCallMainAndExit]
\\ 1:
\\1:
// The `gp` register on MIPS serves a similar purpose to `r2` (ToC pointer) on PPC64.
\\ lw $gp, 0($ra)
\\ nop
\\ subu $gp, $ra, $gp
\\ lw $25, 4($ra)
\\ addu $25, $25, $gp
\\ move $ra, $0
\\ lw $t9, 4($ra)
\\ nop
\\ addu $t9, $t9, $gp
\\ move $ra, $zero
\\ move $a0, $sp
\\ and $sp, -8
\\ subu $sp, $sp, 16
\\ jalr $25
\\ jalr $t9
,
.mips64, .mips64el =>
\\ move $fp, $0
\\ move $fp, $zero
// This is needed because early MIPS versions don't support misaligned loads. Without
// this directive, the hidden `nop` inserted to fill the delay slot after `bal` would
// cause the two doublewords to be aligned to 4 bytes instead of 8.
@ -350,17 +352,17 @@ fn _start() callconv(.naked) noreturn {
\\ bal 1f
\\ .gpdword .
\\ .gpdword %[posixCallMainAndExit]
\\ 1:
\\1:
// The `gp` register on MIPS serves a similar purpose to `r2` (ToC pointer) on PPC64.
\\ ld $gp, 0($ra)
\\ dsubu $gp, $ra, $gp
\\ ld $25, 8($ra)
\\ daddu $25, $25, $gp
\\ move $ra, $0
\\ ld $t9, 8($ra)
\\ daddu $t9, $t9, $gp
\\ move $ra, $zero
\\ move $a0, $sp
\\ and $sp, -16
\\ dsubu $sp, $sp, 16
\\ jalr $25
\\ jalr $t9
,
.powerpc, .powerpcle =>
// Set up the initial stack frame, and clear the back chain pointer.