Ticket #9445: boost-x32-context.patch

libs/context/src/asm/jump_x86_64_sysv_elf_gas.S

@@ -38 +38 @@
  *                                                                                      *
  * **************************************************************************************/
 
+#ifdef __ILP32__
+# define SIZEOF_FCONTEXT_T 0x50
+#else
+# define SIZEOF_FCONTEXT_T 0x58
+#endif
+
 .text
 .globl jump_fcontext
 .type jump_fcontext,@function
@@ -53 +59 @@
     cmp      $0,         %rcx
     je       1f
 
-    stmxcsr  0x50(%rdi)             /* save MMX control and status word */
-    fnstcw   0x54(%rdi)             /* save x87 control word */
+    stmxcsr  (SIZEOF_FCONTEXT_T - 8)(%rdi)             /* save MMX control and status word */
+    fnstcw   (SIZEOF_FCONTEXT_T - 4)(%rdi)             /* save x87 control word */
 
-    ldmxcsr  0x50(%rsi)             /* restore MMX control and status word */
-    fldcw    0x54(%rsi)             /* restore x87 control word */
+    ldmxcsr  (SIZEOF_FCONTEXT_T - 8)(%rsi)             /* restore MMX control and status word */
+    fldcw    (SIZEOF_FCONTEXT_T - 4)(%rsi)             /* restore x87 control word */
 1:
 
     leaq     0x8(%rsp),  %rax       /* exclude the return address and save as stack pointer */

libs/context/src/asm/make_x86_64_sysv_elf_gas.S

@@ -38 +38 @@
  *                                                                                      *
  * **************************************************************************************/
 
+#ifdef __ILP32__
+# define SIZEOF_FCONTEXT_T 0x50
+#else
+# define SIZEOF_FCONTEXT_T 0x58
+#endif
+
 .text
 .globl make_fcontext
 .type make_fcontext,@function
 .align 16
-make_fcontext:
-    leaq   -0x58(%rdi),    %rax        /* reserve space for fcontext_t at top of context stack */
+make_fcontext: // (rax, rsi, rdx)
+    leaq   -SIZEOF_FCONTEXT_T(%rdi), %rax /* reserve space for fcontext_t at top of context stack */
 
     /* shift address in RAX to lower 16 byte boundary */
     /* == pointer to fcontext_t and address of context stack */
     andq   $-16,           %rax
 
+#ifdef __ILP32__
+    mov    %edi,           0x40(%rax) /* save address of context stack pointer (base) in fcontext_t */
+    mov    %esi,           0x44(%rax) /* save context stack size in fcontext_t */
+    mov    %edx,           0x38(%rax) /* save address of context function in fcontext_t */
+#else
     movq   %rdi,           0x40(%rax) /* save address of context stack pointer (base) in fcontext_t */
     movq   %rsi,           0x48(%rax) /* save context stack size in fcontext_t */
     movq   %rdx,           0x38(%rax) /* save address of context function in fcontext_t */
+#endif
 
-    stmxcsr  0x50(%rax)                /* save MMX control and status word */
-    fnstcw   0x54(%rax)                /* save x87 control word */
+    stmxcsr  (SIZEOF_FCONTEXT_T - 8)(%rax)                /* save MMX control and status word */
+    fnstcw   (SIZEOF_FCONTEXT_T - 4)(%rax)                /* save x87 control word */
 
+#ifdef __ILP32__
+    leaq   -0x10(%rax),     %rdx       /* reserve space for the return address on context stack, (RSP - 0x8) % 16 == 0 */
+    mov    %edx,            0x30(%rax) /* save address in RDX as stack pointer for context function */
+#else
     leaq   -0x8(%rax),      %rdx       /* reserve space for the return address on context stack, (RSP - 0x8) % 16 == 0 */
     movq   %rdx,            0x30(%rax) /* save address in RDX as stack pointer for context function */
+#endif
 
     leaq   finish(%rip),    %rcx       /* compute abs address of label finish */
     movq   %rcx,            (%rdx)     /* save address of finish as return address for context function */