commit b8d776928a0b0092830ee632b1c57c8bcf9391ea (tree)
parent f3da54f53c1db1484b00657de18e3677358549cd
Author: Alex Rønne Petersen <alex@alexrp.com>
Date: Sat, 18 Oct 2025 01:56:20 +0200
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.
Diffstat:
5 files changed, 223 insertions(+), 232 deletions(-)
diff --git a/lib/std/os/linux/mips.zig b/lib/std/os/linux/mips.zig
@@ -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
);
}
diff --git a/lib/std/os/linux/mips64.zig b/lib/std/os/linux/mips64.zig
@@ -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
);
}
diff --git a/lib/std/os/linux/mipsn32.zig b/lib/std/os/linux/mipsn32.zig
@@ -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 $v0, 5058 # SYS_exit
\\ syscall
);
}
diff --git a/lib/std/pie.zig b/lib/std/pie.zig
@@ -121,8 +121,9 @@ inline fn getDynamicSymbol() [*]const elf.Dyn {
\\ .hidden _DYNAMIC
\\ bal 1f
\\ .gpword _DYNAMIC
- \\ 1:
+ \\1:
\\ lw %[ret], 0($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),
diff --git a/lib/std/start.zig b/lib/std/start.zig
@@ -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.
