Add support for powerpc

CMakeLists.txt

@@ -84,6 +84,8 @@ elseif(CMU_OS_POSIX AND CMU_ARCH_RISCV)
   set(asm_sources src/fiber_asm_riscv_elf.S)
 elseif(CMU_OS_POSIX AND CMU_ARCH_PPC AND FIBER_BITS_64 AND CMU_LITTLE_ENDIAN)
   set(asm_sources src/fiber_asm_ppc64le_elf2.S)
+elseif(CMU_OS_POSIX AND CMU_ARCH_PPC AND FIBER_BITS_32)
+  set(asm_sources src/fiber_asm_ppc_mach.S)
 endif()
 
 if(CMU_COMP_MSVC)

include/fiber/fiber_mach.h

@@ -119,6 +119,17 @@
         double *f[18];        /* f14 - f31 */                                  \
         double *v[12 * 2 + 1] /* v20 - v31, adjusted to be 16 byte aligned */
 
+#elif HU_ARCH_PPC_P && HU_BITS_32_P && HU_OBJFMT_MACHO_P
+#    define FIBER_TARGET_PPC_MACH 1
+#    define FIBER_DEFAULT_STACK_ALIGNMENT 16
+#    define FIBER_ARCH_REGS                                                    \
+        uint32_t cr;                                                           \
+        uint32_t vrsave;                                                       \
+        void *lr;             /* r0 */                                         \
+        void *sp;             /* r1 */                                         \
+        void *r[19];          /* r13 - r31 */                                  \
+        double *f[18]         /* f14 - f31 */
+
 #else
 #    error "fiber: system/architecture target not supported"
 #endif

src/fiber.c

@@ -8,10 +8,16 @@
 #include <stdlib.h>
 #include <string.h>
 
+#ifdef __APPLE__
+#include <AvailabilityMacros.h>
+#endif
+
 #if HU_OS_POSIX_P
 #    include <sys/mman.h>
 #    include <unistd.h>
-#    if HU_C_11_P
+#    if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED < 101300
+#        define USE_POSIX_MEMALIGN 1 /* No aligned_alloc on macOS < 10.13 */
+#    elif HU_C_11_P
 #        define ALIGNED_ALLOC aligned_alloc
 #    elif HU_OS_BSD_P || defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L
 #        define USE_POSIX_MEMALIGN 1

src/fiber_asm_ppc_mach.S

@@ -0,0 +1,152 @@
+.machine ppc7400
+.text
+.align 2
+
+.macro check_stack_alignment
+#ifdef FIBER_ASM_CHECK_ALIGNMENT
+  rlwinm r0, r1, 0, 28, 31 ; r1 & 0xF
+  cmpwi r0, 0
+  bne _align_check_failed
+#endif
+.endm
+
+; Switch fiber context: r3 = old fiber, r4 = new fiber
+  .globl _fiber_asm_switch
+_fiber_asm_switch:
+  ; Save volatile state in old fiber
+  mfcr r5
+  stw  r5, 0(r3)
+  mflr r0
+  stw  r0, 4(r3)
+  stw  r1, 8(r3)
+
+  stw r13, 12(r3)
+  stw r14, 16(r3)
+  stw r15, 20(r3)
+  stw r16, 24(r3)
+  stw r17, 28(r3)
+  stw r18, 32(r3)
+  stw r19, 36(r3)
+  stw r20, 40(r3)
+  stw r21, 44(r3)
+  stw r22, 48(r3)
+  stw r23, 52(r3)
+  stw r24, 56(r3)
+  stw r25, 60(r3)
+  stw r26, 64(r3)
+  stw r27, 68(r3)
+  stw r28, 72(r3)
+  stw r29, 76(r3)
+  stw r30, 80(r3)
+  stw r31, 84(r3)
+
+  stfd f14, 88(r3)
+  stfd f15, 96(r3)
+  stfd f16, 104(r3)
+  stfd f17, 112(r3)
+  stfd f18, 120(r3)
+  stfd f19, 128(r3)
+  stfd f20, 136(r3)
+  stfd f21, 144(r3)
+  stfd f22, 152(r3)
+  stfd f23, 160(r3)
+  stfd f24, 168(r3)
+  stfd f25, 176(r3)
+  stfd f26, 184(r3)
+  stfd f27, 192(r3)
+  stfd f28, 200(r3)
+  stfd f29, 208(r3)
+  stfd f30, 216(r3)
+  stfd f31, 224(r3)
+
+  ; Restore volatile state from new fiber
+  lwz  r5, 0(r4)
+  mtcrf 0xFF, r5
+  lwz  r0, 4(r4)
+  mtlr r0
+  lwz  r1, 8(r4)
+
+  lwz r13, 12(r4)
+  lwz r14, 16(r4)
+  lwz r15, 20(r4)
+  lwz r16, 24(r4)
+  lwz r17, 28(r4)
+  lwz r18, 32(r4)
+  lwz r19, 36(r4)
+  lwz r20, 40(r4)
+  lwz r21, 44(r4)
+  lwz r22, 48(r4)
+  lwz r23, 52(r4)
+  lwz r24, 56(r4)
+  lwz r25, 60(r4)
+  lwz r26, 64(r4)
+  lwz r27, 68(r4)
+  lwz r28, 72(r4)
+  lwz r29, 76(r4)
+  lwz r30, 80(r4)
+  lwz r31, 84(r4)
+
+  lfd  f14, 88(r4)
+  lfd  f15, 96(r4)
+  lfd  f16, 104(r4)
+  lfd  f17, 112(r4)
+  lfd  f18, 120(r4)
+  lfd  f19, 128(r4)
+  lfd  f20, 136(r4)
+  lfd  f21, 144(r4)
+  lfd  f22, 152(r4)
+  lfd  f23, 160(r4)
+  lfd  f24, 168(r4)
+  lfd  f25, 176(r4)
+  lfd  f26, 184(r4)
+  lfd  f27, 192(r4)
+  lfd  f28, 200(r4)
+  lfd  f29, 208(r4)
+  lfd  f30, 216(r4)
+  lfd  f31, 224(r4)
+
+  blr
+
+; Invoke: r1 points to stack
+  .globl _fiber_asm_invoke
+_fiber_asm_invoke:
+  lwz r3, 0(r1)    ; arg
+  lwz r12, 4(r1)   ; func
+  mtlr r12
+  stwu r1, -48(r1) ; new frame
+  stw  r2, 8(r1)
+  blrl
+  lwz r2, 8(r1)
+  lwz r0, 44(r1)
+  mtlr r0
+  lwz r3, 40(r1)
+  mr  r1, r3
+  blr
+
+; Execute on stack: r4=function, r5=stack, r6=arg, r31 preserved
+  .globl _fiber_asm_exec_on_stack
+_fiber_asm_exec_on_stack:
+  mflr r0
+  mr   r7, r31
+  mr   r12, r4
+  mtlr r12
+  mr   r31, r1
+  stw  r0, 8(r1)
+  mr   r1, r5
+  stw  r7, -4(r1)
+  stwu r1, -48(r1)
+  stw  r2, 8(r1)
+  mr   r3, r6
+  blrl
+  lwz  r2, 8(r1)
+  mr   r3, r31
+  lwz  r31, 44(r1)
+  mr   r1, r3
+  lwz  r0, 8(r1)
+  mtlr r0
+  blr
+
+#ifdef FIBER_ASM_CHECK_ALIGNMENT
+_align_check_failed:
+  b _fiber_align_check_failed
+#endif