diff --git a/runtime/src/z_AIX_asm.S b/runtime/src/z_AIX_asm.S
new file mode 100644
index 0000000..d711fcb
--- /dev/null
+++ b/runtime/src/z_AIX_asm.S
@@ -0,0 +1,410 @@
+//  z_AIX_asm.S:  - microtasking routines specifically
+//                  written for Power platforms running AIX OS
+
+//
+////===----------------------------------------------------------------------===//
+////
+//// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+//// See https://llvm.org/LICENSE.txt for license information.
+//// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+////
+////===----------------------------------------------------------------------===//
+//
+
+// -----------------------------------------------------------------------
+// macros
+// -----------------------------------------------------------------------
+
+#include "kmp_config.h"
+
+#if KMP_OS_AIX
+//------------------------------------------------------------------------
+// int
+// __kmp_invoke_microtask( void (*pkfn) (int *gtid, int *tid, ...),
+//                         int gtid, int tid,
+//                         int argc, void *p_argv[]
+// #if OMPT_SUPPORT
+//                         ,
+//                         void **exit_frame_ptr
+// #endif
+//                       ) {
+// #if OMPT_SUPPORT
+//   *exit_frame_ptr = OMPT_GET_FRAME_ADDRESS(0);
+// #endif
+//
+//   (*pkfn)( & gtid, & tid, p_argv[0], ... );
+//
+// // FIXME: This is done at call-site and can be removed here.
+// #if OMPT_SUPPORT
+//   *exit_frame_ptr = 0;
+// #endif
+//
+//   return 1;
+// }
+//
+// parameters:
+//   r3: pkfn
+//   r4: gtid
+//   r5: tid
+//   r6: argc
+//   r7: p_argv
+//   r8: &exit_frame
+//
+// return:  r3 (always 1/TRUE)
+//
+
+#if KMP_ARCH_PPC64_XCOFF
+
+    .globl  __kmp_invoke_microtask[DS]
+    .globl  .__kmp_invoke_microtask
+    .align  4
+    .csect __kmp_invoke_microtask[DS],3
+    .vbyte  8, .__kmp_invoke_microtask
+    .vbyte  8, TOC[TC0]
+    .vbyte  8, 0
+    .csect .text[PR],2
+    .machine "pwr7"
+.__kmp_invoke_microtask:
+
+
+// -- Begin __kmp_invoke_microtask
+// mark_begin;
+
+// We need to allocate a stack frame large enough to hold all of the parameters
+// on the stack for the microtask plus what this function needs. That's 48
+// bytes under the XCOFF64 ABI, plus max(64, 8*(2 + argc)) for
+// the parameters to the microtask (gtid, tid, argc elements of p_argv),
+// plus 8 bytes to store the values of r4 and r5, and 8 bytes to store r31.
+// With OMP-T support, we need an additional 8 bytes to save r30 to hold
+// a copy of r8.
+// Stack offsets relative to stack pointer:
+//   r31: -8, r30: -16, gtid: -20, tid: -24
+
+    mflr 0
+    std 31, -8(1)      # Save r31 to the stack
+    std 0, 16(1)       # Save LR to the linkage area
+
+// This is unusual because normally we'd set r31 equal to r1 after the stack
+// frame is established. In this case, however, we need to dynamically compute
+// the stack frame size, and so we keep a direct copy of r1 to access our
+// register save areas and restore the r1 value before returning.
+    mr 31, 1
+
+// Compute the size of the "argc" portion of the parameter save area.
+// The parameter save area is always at least 64 bytes long (i.e. 8 regs)
+// The microtask has (2 + argc) parameters, so if argc <= 6, we need to
+// to allocate 8*6 bytes, not 8*argc.
+    li 0, 6
+    cmpwi 0, 6, 6
+    iselgt 0, 6, 0     # r0 = (argc > 6)? argc : 6
+    sldi 0, 0, 3       # r0 = 8 * max(argc, 6)
+
+// Compute the size necessary for the local stack frame.
+// 88 = 48 + 4 (for r4) + 4 (for r5) + 8 (for r31) + 8 (for OMP-T r30) +
+//      8 (parameter gtid) + 8 (parameter tid)
+    li 12, 88
+    add 12, 0, 12
+    neg 12, 12
+
+// We need to make sure that the stack frame stays aligned (to 16 bytes).
+    li 0, -16
+    and 12, 0, 12
+
+// Establish the local stack frame.
+    stdux 1, 1, 12
+
+#if OMPT_SUPPORT
+    std 30, -16(31)    # Save r30 to the stack
+    std 1, 0(8)
+    mr 30, 8
+#endif
+
+// Store gtid and tid to the stack because they're passed by reference to the microtask.
+    stw 4, -20(31)     # Save gtid to the stack
+    stw 5, -24(31)     # Save tid to the stack
+
+    mr 12, 6           # r12 = argc
+    mr 4, 7            # r4 = p_argv
+
+    cmpwi 0, 12, 1
+    blt 0, .Lcall      # if (argc < 1) goto .Lcall
+
+    ld 5, 0(4)         # r5 = p_argv[0]
+
+    cmpwi 0, 12, 2
+    blt 0, .Lcall      # if (argc < 2) goto .Lcall
+
+    ld 6, 8(4)         # r6 = p_argv[1]
+
+    cmpwi 0, 12, 3
+    blt 0, .Lcall      # if (argc < 3) goto .Lcall
+
+    ld 7, 16(4)        # r7 = p_argv[2]
+
+    cmpwi 0, 12, 4
+    blt 0, .Lcall      # if (argc < 4) goto .Lcall
+
+    ld 8, 24(4)        # r8 = p_argv[3]
+
+    cmpwi 0, 12, 5
+    blt 0, .Lcall      # if (argc < 5) goto .Lcall
+
+    ld 9, 32(4)        # r9 = p_argv[4]
+
+    cmpwi 0, 12, 6
+    blt 0, .Lcall      # if (argc < 6) goto .Lcall
+
+    ld 10, 40(4)       # r10 = p_argv[5]
+
+    cmpwi 0, 12, 7
+    blt 0, .Lcall      # if (argc < 7) goto .Lcall
+
+// There are more than 6 microtask parameters, so we need to store the
+// remainder to the stack.
+    addi 12, 12, -6    # argc -= 6
+    mtctr 12
+
+// These are set to 8 bytes before the first desired store address (we're using
+// pre-increment loads and stores in the loop below). The parameter save area
+// for the microtask begins 48 + 8*8 == 112 bytes above r1 for XCOFF64.
+    addi 4, 4, 40      # p_argv = p_argv + 5
+                       # (i.e. skip the 5 elements we already processed)
+    addi 12, 1, 104    # r12 = stack offset (112 - 8)
+
+.Lnext:
+    ldu 0, 8(4)
+    stdu 0, 8(12)
+    bdnz .Lnext
+
+.Lcall:
+    std 2, 40(1)     # Save the TOC pointer to the linkage area
+// Load the actual function address from the function descriptor.
+    ld 12, 0(3)      # Function address
+    ld 2, 8(3)       # TOC pointer
+    ld 11, 16(3)     # Environment pointer
+
+    addi 3, 31, -20  # r3 = &gtid
+    addi 4, 31, -24  # r4 = &tid
+
+    mtctr 12         # CTR = function address
+    bctrl            # Branch to CTR
+    ld 2, 40(1)      # Restore TOC pointer from linkage area
+
+#if OMPT_SUPPORT
+    li 3, 0
+    std 3, 0(30)
+#endif
+
+    li 3, 1
+
+#if OMPT_SUPPORT
+    ld 30, -16(31)   # Restore r30 from the saved value on the stack
+#endif
+
+    mr 1, 31
+    ld 31, -8(1)     # Restore r31 from the saved value on the stack
+    ld 0, 16(1)
+    mtlr 0           # Restore LR from the linkage area
+    blr              # Branch to LR
+
+#else  // KMP_ARCH_PPC_XCOFF
+
+    .globl  __kmp_invoke_microtask[DS]
+    .globl  .__kmp_invoke_microtask
+    .align  4
+    .csect __kmp_invoke_microtask[DS],2
+    .vbyte  4, .__kmp_invoke_microtask
+    .vbyte  4, TOC[TC0]
+    .vbyte  4, 0
+    .csect .text[PR],2
+    .machine "pwr7"
+.__kmp_invoke_microtask:
+
+
+// -- Begin __kmp_invoke_microtask
+// mark_begin;
+
+// We need to allocate a stack frame large enough to hold all of the parameters
+// on the stack for the microtask plus what this function needs. That's 24
+// bytes under the XCOFF ABI, plus max(32, 8*(2 + argc)) for
+// the parameters to the microtask (gtid, tid, argc elements of p_argv),
+// plus 8 bytes to store the values of r4 and r5, and 4 bytes to store r31.
+// With OMP-T support, we need an additional 4 bytes to save r30 to hold
+// a copy of r8.
+// Stack offsets relative to stack pointer:
+//   r31: -4, r30: -8, gtid: -12, tid: -16
+
+    mflr 0
+    stw 31, -4(1)      # Save r31 to the stack
+    stw 0, 8(1)        # Save LR to the linkage area
+
+// This is unusual because normally we'd set r31 equal to r1 after the stack
+// frame is established. In this case, however, we need to dynamically compute
+// the stack frame size, and so we keep a direct copy of r1 to access our
+// register save areas and restore the r1 value before returning.
+    mr 31, 1
+
+// Compute the size of the "argc" portion of the parameter save area.
+// The parameter save area is always at least 32 bytes long (i.e. 8 regs)
+// The microtask has (2 + argc) parameters, so if argc <= 6, we need to
+// to allocate 4*6 bytes, not 4*argc.
+    li 0, 6
+    cmpwi 0, 6, 6
+    iselgt 0, 6, 0     # r0 = (argc > 6)? argc : 6
+    slwi 0, 0, 2       # r0 = 4 * max(argc, 6)
+
+// Compute the size necessary for the local stack frame.
+// 56 = 32 + 4 (for r4) + 4 (for r5) + 4 (for r31) + 4 (for OMP-T r30) +
+//      4 (parameter gtid) + 4 (parameter tid)
+    li 12, 56
+    add 12, 0, 12
+    neg 12, 12
+
+// We need to make sure that the stack frame stays aligned (to 16 bytes).
+    li 0, -16
+    and 12, 0, 12
+
+// Establish the local stack frame.
+    stwux 1, 1, 12
+
+#if OMPT_SUPPORT
+    stw 30, -8(31)     # Save r30 to the stack
+    stw 1, 0(8)
+    mr 30, 8
+#endif
+
+// Store gtid and tid to the stack because they're passed by reference to the microtask.
+    stw 4, -12(31)     # Save gtid to the stack
+    stw 5, -16(31)     # Save tid to the stack
+
+    mr 12, 6           # r12 = argc
+    mr 4, 7            # r4 = p_argv
+
+    cmpwi 0, 12, 1
+    blt 0, .Lcall      # if (argc < 1) goto .Lcall
+
+    lwz 5, 0(4)        # r5 = p_argv[0]
+
+    cmpwi 0, 12, 2
+    blt 0, .Lcall      # if (argc < 2) goto .Lcall
+
+    lwz 6, 4(4)        # r6 = p_argv[1]
+
+    cmpwi 0, 12, 3
+    blt 0, .Lcall      # if (argc < 3) goto .Lcall
+
+    lwz 7, 8(4)        # r7 = p_argv[2]
+
+    cmpwi 0, 12, 4
+    blt 0, .Lcall      # if (argc < 4) goto .Lcall
+
+    lwz 8, 12(4)       # r8 = p_argv[3]
+
+    cmpwi 0, 12, 5
+    blt 0, .Lcall      # if (argc < 5) goto .Lcall
+
+    lwz 9, 16(4)       # r9 = p_argv[4]
+
+    cmpwi 0, 12, 6
+    blt 0, .Lcall      # if (argc < 6) goto .Lcall
+
+    lwz 10, 20(4)      # r10 = p_argv[5]
+
+    cmpwi 0, 12, 7
+    blt 0, .Lcall      # if (argc < 7) goto .Lcall
+
+// There are more than 6 microtask parameters, so we need to store the
+// remainder to the stack.
+    addi 12, 12, -6    # argc -= 6
+    mtctr 12
+
+// These are set to 4 bytes before the first desired store address (we're using
+// pre-increment loads and stores in the loop below). The parameter save area
+// for the microtask begins 24 + 4*8 == 56 bytes above r1 for XCOFF.
+    addi 4, 4, 20      # p_argv = p_argv + 5
+                       # (i.e. skip the 5 elements we already processed)
+    addi 12, 1, 52     # r12 = stack offset (56 - 4)
+
+.Lnext:
+    lwzu 0, 4(4)
+    stwu 0, 4(12)
+    bdnz .Lnext
+
+.Lcall:
+    stw 2, 20(1)     # Save the TOC pointer to the linkage area
+// Load the actual function address from the function descriptor.
+    lwz 12, 0(3)     # Function address
+    lwz 2, 4(3)      # TOC pointer
+    lwz 11, 8(3)     # Environment pointer
+
+    addi 3, 31, -12  # r3 = &gtid
+    addi 4, 31, -16  # r4 = &tid
+
+    mtctr 12         # CTR = function address
+    bctrl            # Branch to CTR
+    lwz 2, 20(1)     # Restore TOC pointer from linkage area
+
+#if OMPT_SUPPORT
+    li 3, 0
+    stw 3, 0(30)
+#endif
+
+    li 3, 1
+
+#if OMPT_SUPPORT
+    lwz 30, -8(31)   # Restore r30 from the saved value on the stack
+#endif
+
+    mr 1, 31
+    lwz 31, -4(1)    # Restore r31 from the saved value on the stack
+    lwz 0, 8(1)
+    mtlr 0           # Restore LR from the linkage area
+    blr              # Branch to LR
+
+#endif // KMP_ARCH_PPC64_XCOFF
+
+.Lfunc_end0:
+    .vbyte  4, 0x00000000           # Traceback table begin
+    .byte   0x00                    # Version = 0
+    .byte   0x09                    # Language = CPlusPlus
+    .byte   0x20                    # -IsGlobaLinkage, -IsOutOfLineEpilogOrPrologue
+                                    # +HasTraceBackTableOffset, -IsInternalProcedure
+                                    # -HasControlledStorage, -IsTOCless
+                                    # -IsFloatingPointPresent
+                                    # -IsFloatingPointOperationLogOrAbortEnabled
+    .byte   0x61                    # -IsInterruptHandler, +IsFunctionNamePresent, +IsAllocaUsed
+                                    # OnConditionDirective = 0, -IsCRSaved, +IsLRSaved
+    .byte   0x80                    # +IsBackChainStored, -IsFixup, NumOfFPRsSaved = 0
+#if OMPT_SUPPORT
+    .byte   0x02                    # -HasExtensionTable, -HasVectorInfo, NumOfGPRsSaved = 2
+    .byte   0x06                    # NumberOfFixedParms = 6
+#else
+    .byte   0x01                    # -HasExtensionTable, -HasVectorInfo, NumOfGPRsSaved = 1
+    .byte   0x05                    # NumberOfFixedParms = 5
+#endif
+    .byte   0x01                    # NumberOfFPParms = 0, +HasParmsOnStack
+    .vbyte  4, 0x00000000           # Parameter type = i, i, i, i, i
+    .vbyte  4, .Lfunc_end0-.__kmp_invoke_microtask # Function size
+    .vbyte  2, 0x0016               # Function name len = 22
+    .byte   "__kmp_invoke_microtask" # Function Name
+    .byte   0x1f                    # AllocaRegister = 31
+                                    # -- End function
+
+// -- End  __kmp_invoke_microtask
+
+// Support for unnamed common blocks.
+
+    .comm .gomp_critical_user_, 32, 3
+#if KMP_ARCH_PPC64_XCOFF
+    .csect __kmp_unnamed_critical_addr[RW],3
+#else
+    .csect __kmp_unnamed_critical_addr[RW],2
+#endif
+    .globl __kmp_unnamed_critical_addr[RW]
+    .ptr .gomp_critical_user_
+
+// -- End unnamed common block
+
+    .toc
+
+#endif // KMP_OS_AIX