[newlib-cygwin/main] Cygwin: gendef: Implement setjmp for AArch64

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=64cc55376e1cd76799c98ce014a8f49936363296

commit 64cc55376e1cd76799c98ce014a8f49936363296
Author:     Thirumalai Nagalingam <thirumalai.nagalingam@multicorewareinc.com>
AuthorDate: Sat Dec 6 18:13:28 2025 +0530
Commit:     Corinna Vinschen <corinna@vinschen.de>
CommitDate: Wed Mar 11 15:49:20 2026 +0100

    Cygwin: gendef: Implement setjmp for AArch64
    
    Author: Radek Bartoň <radek.barton@microsoft.com>
    Co-authored-by: Thirumalai Nagalingam <thirumalai.nagalingam@multicorewareinc.com>
    
    Signed-off-by: Thirumalai Nagalingam <thirumalai.nagalingam@multicorewareinc.com>

Diff:
---
 winsup/cygwin/scripts/gendef | 55 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/winsup/cygwin/scripts/gendef b/winsup/cygwin/scripts/gendef
index d7426c008473..826d76e75d90 100755
--- a/winsup/cygwin/scripts/gendef
+++ b/winsup/cygwin/scripts/gendef
@@ -864,7 +864,62 @@ sigsetjmp:
 	.seh_endproc
 
 	.globl  setjmp
+	.seh_proc setjmp
 setjmp:
+	// prologue
+	stp	fp, lr, [sp, #-0x10]!      	// push frame pointer (x29) and link register (x30)
+	mov	fp, sp                      	// set frame pointer
+	.seh_endprologue
+
+	// save callee-saved registers from jump buffer
+	stp	x19, x20, [x0, #0x08]       	// save x19, x20
+	stp	x21, x22, [x0, #0x18]       	// save x21, x22
+	stp	x23, x24, [x0, #0x28]       	// save x23, x24
+	stp	x25, x26, [x0, #0x38]       	// save x25, x26
+	stp	x27, x28, [x0, #0x48]       	// save x27, x28
+	stp	x29, x30, [x0, #0x58]       	// save frame ptr (x29) and return addr (x30)
+
+	mov	x1, sp				// get the current stack pointer
+	str	x1, [x0, #0x68]			// save SP
+
+	mrs	x1, fpcr			// get fp control register
+	str	x1, [x0, #0x70]			// save FPCR
+	mrs	x1, fpsr			// get fp status register
+	str	x1, [x0, #0x78]			// save FPSR
+
+	// save fp registers (d8-d15)
+	stp	d8,  d9,  [x0, #0x80]        	// save d8, d9
+	stp	d10, d11, [x0, #0x90]        	// save d10, d11
+	stp	d12, d13, [x0, #0xA0]        	// save d12, d13
+	stp	d14, d15, [x0, #0xB0]        	// save d14, d15
+
+	mov x9, x0 				// save jmp_buf pointer in x9
+	# // save TLS stack pointer
+	# ldr	x1, [sp]
+	# str	x1, [x0, #0xB8]
+
+	bl	stabilize_sig_stack		// call stabilize_sig_stack (returns TLS in x0)
+
+	// store the stack pointer to jump_buf
+	ldr	x2, =_cygtls.stackptr		// load the symbol address/offset
+	add	x2, x0, x2			// Final address of stackptr
+	ldr	x3, [x2]			// load current value of stackptr
+	str x3, [x0, #0xB8]           		// store stackptr into jmp_buf
+
+	// decrement the stack lock
+	ldr	x2, =_cygtls.stacklock 		// load the symbol address/offset
+	add	x2, x0, x2			// Final address of stacklock
+	ldr	w3, [x2]			// load current stacklock value
+	sub	w3, w3, #1			// decrement
+	str	w3, [x2]			//store back
+
+	mov	w0, #0				// return 0
+
+	// epilogue
+	ldp	fp, lr, [sp], #0x10		// restore saved FP and LR registers
+	ret
+	.seh_endproc
+
 	.globl	siglongjmp
 	.seh_proc siglongjmp
 siglongjmp: