diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -1413,6 +1413,13 @@
   setLibcallName(RTLIB::NEARBYINT_F128, "nearbyintf128");
   setLibcallName(RTLIB::FMA_F128, "fmaf128");
 
+  if (Subtarget.isAIXABI()) {
+    setLibcallName(RTLIB::MEMCPY, isPPC64 ? "___memmove64" : "___memmove");
+    setLibcallName(RTLIB::MEMMOVE, isPPC64 ? "___memmove64" : "___memmove");
+    setLibcallName(RTLIB::MEMSET, isPPC64 ? "___memset64" : "___memset");
+    setLibcallName(RTLIB::BZERO, isPPC64 ? "___bzero64" : "___bzero");
+  }
+
   // With 32 condition bits, we don't need to sink (and duplicate) compares
   // aggressively in CodeGenPrep.
   if (Subtarget.useCRBits()) {
diff --git a/llvm/test/CodeGen/PowerPC/aix-cc-byval-mem.ll b/llvm/test/CodeGen/PowerPC/aix-cc-byval-mem.ll
--- a/llvm/test/CodeGen/PowerPC/aix-cc-byval-mem.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-cc-byval-mem.ll
@@ -87,7 +87,7 @@
 ; 32BIT-DAG:      $r3 = COPY %0
 ; 32BIT-DAG:      $r4 = COPY %1
 ; 32BIT-DAG:      $r5 = COPY %2
-; 32BIT-NEXT:     BL_NOP &".memcpy[PR]", csr_aix32, implicit-def dead $lr, implicit $rm, implicit $r3, implicit $r4, implicit $r5, implicit $r2, implicit-def $r1, implicit-def $r3
+; 32BIT-NEXT:     BL_NOP &".___memmove[PR]", csr_aix32, implicit-def dead $lr, implicit $rm, implicit $r3, implicit $r4, implicit $r5, implicit $r2, implicit-def $r1, implicit-def $r3
 ; 32BIT-NEXT:     ADJCALLSTACKUP 56, 0, implicit-def dead $r1, implicit $r1
 ; 32BIT:          ADJCALLSTACKDOWN 312, 0, implicit-def dead $r1, implicit $r1
 ; 32BIT-DAG:      $r3 = COPY %{{[0-9]+}}
@@ -108,7 +108,7 @@
 ; ASM32BIT-DAG:   lwz 4, L..C{{[0-9]+}}(2)
 ; ASM32BIT-DAG:   li 5, 256
 ; ASM32BIT-DAG:   stw 0, 328(1)
-; ASM32BIT-NEXT:  bl .memcpy[PR]
+; ASM32BIT-NEXT:  bl .___memmove[PR]
 ; ASM32BIT:       bl .test_byval_mem2
 ; ASM32BIT:       addi 1, 1, 320
 
@@ -120,7 +120,7 @@
 ; 64BIT-DAG:      $x3 = COPY %0
 ; 64BIT-DAG:      $x4 = COPY %1
 ; 64BIT-DAG:      $x5 = COPY %2
-; 64BIT-NEXT:     BL8_NOP &".memcpy[PR]", csr_ppc64, implicit-def dead $lr8, implicit $rm, implicit $x3, implicit $x4, implicit $x5, implicit $x2, implicit-def $r1, implicit-def $x3
+; 64BIT-NEXT:     BL8_NOP &".___memmove64[PR]", csr_ppc64, implicit-def dead $lr8, implicit $rm, implicit $x3, implicit $x4, implicit $x5, implicit $x2, implicit-def $r1, implicit-def $x3
 ; 64BIT-NEXT:     ADJCALLSTACKUP 112, 0, implicit-def dead $r1, implicit $r1
 ; 64BIT:          ADJCALLSTACKDOWN 368, 0, implicit-def dead $r1, implicit $r1
 ; 64BIT-DAG:      $x3 = COPY %{{[0-9]+}}
@@ -139,7 +139,7 @@
 ; ASM64BIT-DAG:   ld 4, L..C{{[0-9]+}}(2)
 ; ASM64BIT-DAG:   li 5, 256
 ; ASM64BIT-DAG:   std 0, 384(1)
-; ASM64BIT-NEXT:  bl .memcpy[PR]
+; ASM64BIT-NEXT:  bl .___memmove64[PR]
 ; ASM64BIT:       bl .test_byval_mem2
 ; ASM64BIT:       addi 1, 1, 368
 
@@ -188,7 +188,7 @@
 ; 32BIT-DAG:      $r3 = COPY %2
 ; 32BIT-DAG:      $r4 = COPY %1
 ; 32BIT-DAG:      $r5 = COPY %3
-; 32BIT-NEXT:     BL_NOP &".memcpy[PR]", csr_aix32, implicit-def dead $lr, implicit $rm, implicit $r3, implicit $r4, implicit $r5, implicit $r2, implicit-def $r1, implicit-def $r3
+; 32BIT-NEXT:     BL_NOP &".___memmove[PR]", csr_aix32, implicit-def dead $lr, implicit $rm, implicit $r3, implicit $r4, implicit $r5, implicit $r2, implicit-def $r1, implicit-def $r3
 ; 32BIT-NEXT:     ADJCALLSTACKUP 56, 0, implicit-def dead $r1, implicit $r1
 ; 32BIT:          ADJCALLSTACKDOWN 92, 0, implicit-def dead $r1, implicit $r1
 ; 32BIT-DAG:      $r3 = COPY %{{[0-9]+}}
@@ -209,7 +209,7 @@
 ; ASM32BIT-DAG:   addi 3, 1, 56
 ; ASM32BIT-DAG:   addi 4, [[REG]], 24
 ; ASM32BIT-DAG:   li 5, 33
-; ASM32BIT-NEXT:  bl .memcpy[PR]
+; ASM32BIT-NEXT:  bl .___memmove[PR]
 ; ASM32BIT-DAG:   lwz 5, 0([[REG]])
 ; ASM32BIT-DAG:   lwz 6, 4([[REG]])
 ; ASM32BIT-DAG:   lwz 7, 8([[REG]])
@@ -306,7 +306,7 @@
 ; 32BIT-DAG:      $r3 = COPY %3
 ; 32BIT-DAG:      $r4 = COPY %4
 ; 32BIT-DAG:      $r5 = COPY %5
-; 32BIT-NEXT:     BL_NOP &".memcpy[PR]", csr_aix32, implicit-def dead $lr, implicit $rm, implicit $r3, implicit $r4, implicit $r5, implicit $r2, implicit-def $r1, implicit-def $r3
+; 32BIT-NEXT:     BL_NOP &".___memmove[PR]", csr_aix32, implicit-def dead $lr, implicit $rm, implicit $r3, implicit $r4, implicit $r5, implicit $r2, implicit-def $r1, implicit-def $r3
 ; 32BIT-NEXT:     ADJCALLSTACKUP 56, 0, implicit-def dead $r1, implicit $r1
 ; 32BIT:          ADJCALLSTACKDOWN 316, 0, implicit-def dead $r1, implicit $r1
 ; 32BIT-DAG:      $r3 = COPY %{{[0-9]+}}
@@ -331,7 +331,7 @@
 ; ASM32BIT-DAG:   addi 3, 1, 60
 ; ASM32BIT-DAG:   lwz 4, L..C{{[0-9]+}}(2)
 ; ASM32BIT-DAG:   li 5, 256
-; ASM32BIT-NEXT:  bl .memcpy[PR]
+; ASM32BIT-NEXT:  bl .___memmove[PR]
 ; ASM32BIT-DAG:   lwz 4, 0([[REG1]])
 ; ASM32BIT-DAG:   lwz 5, 4([[REG1]])
 ; ASM32BIT-DAG:   lwz 6, 8([[REG1]])
@@ -351,7 +351,7 @@
 ; 64BIT-DAG:      $x3 = COPY %2
 ; 64BIT-DAG:      $x4 = COPY %1
 ; 64BIT-DAG:      $x5 = COPY %3
-; 64BIT-NEXT:     BL8_NOP &".memcpy[PR]", csr_ppc64, implicit-def dead $lr8, implicit $rm, implicit $x3, implicit $x4, implicit $x5, implicit $x2, implicit-def $r1, implicit-def $x3
+; 64BIT-NEXT:     BL8_NOP &".___memmove64[PR]", csr_ppc64, implicit-def dead $lr8, implicit $rm, implicit $x3, implicit $x4, implicit $x5, implicit $x2, implicit-def $r1, implicit-def $x3
 ; 64BIT-NEXT:     ADJCALLSTACKUP 112, 0, implicit-def dead $r1, implicit $r1
 ; 64BIT:          ADJCALLSTACKDOWN 344, 0, implicit-def dead $r1, implicit $r1
 ; 64BIT-DAG:      $x3 = COPY %{{[0-9]+}}
@@ -370,7 +370,7 @@
 ; ASM64BIT-DAG:   addi 3, 1, 112
 ; ASM64BIT-DAG:   addi 4, [[REG1]], 24
 ; ASM64BIT-DAG:   li 5, 232
-; ASM64BIT-NEXT:  bl .memcpy[PR]
+; ASM64BIT-NEXT:  bl .___memmove64[PR]
 ; ASM64BIT-DAG:   ld [[REG2:[0-9]+]], L..C{{[0-9]+}}(2)
 ; ASM64BIT-DAG:   ld 4, 0([[REG2]])
 ; ASM64BIT-DAG:   ld 5, 8([[REG2]])
diff --git a/llvm/test/CodeGen/PowerPC/aix-llvm-intrinsic.ll b/llvm/test/CodeGen/PowerPC/aix-llvm-intrinsic.ll
--- a/llvm/test/CodeGen/PowerPC/aix-llvm-intrinsic.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-llvm-intrinsic.ll
@@ -1,8 +1,8 @@
 ; RUN: llc -verify-machineinstrs -mtriple powerpc-ibm-aix-xcoff -mcpu=pwr4 -mattr=-altivec < %s | \
-; RUN:   FileCheck %s
+; RUN:   FileCheck --check-prefix=CHECK32 %s
 
 ; RUN: llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff -mcpu=pwr4 -mattr=-altivec < %s | \
-; RUN:   FileCheck %s
+; RUN:   FileCheck --check-prefix=CHECK64 %s
 
 ; RUN: llc -verify-machineinstrs -mtriple powerpc-ibm-aix-xcoff -mcpu=pwr4 \
 ; RUN:     -mattr=-altivec -filetype=obj -o %t.o < %s
@@ -33,9 +33,10 @@
 ; CHECK-NEXT: # %bb.0:                                # %entry
 ; CHECK-NEXT:         mflr 0
 
-; CHECK:              bl .memset
-
-; CHECK:              .extern .memset
+; CHECK32:              bl .___memset
+; CHECK32:              .extern .___memset
+; CHECK64:              bl .___memset64
+; CHECK64:              .extern .___memset64
 
 ; CHECKSYM:        Symbol {
 ; CHECKSYM-NEXT:     Index: 0
@@ -49,7 +50,8 @@
 ; CHECKSYM-NEXT:   }
 ; CHECKSYM-NEXT:   Symbol {
 ; CHECKSYM-NEXT:     Index: 1
-; CHECKSYM-NEXT:     Name: .memset
+; CHECKSYM32-NEXT:     Name: .___memset
+; CHECKSYM64-NEXT:     Name: .___memset64
 ; CHECKSYM-NEXT:     Value (RelocatableAddress): 0x0
 ; CHECKSYM-NEXT:     Section: N_UNDEF
 ; CHECKSYM-NEXT:     Type: 0x0
@@ -83,5 +85,5 @@
 ; CHECKRELOC-NEXT:       10: 80 83 00 04                        lwz 4, 4(3)
 ; CHECKRELOC-NEXT:       14: 7c 85 23 78                        mr 5, 4
 ; CHECKRELOC-NEXT:       18: 4b ff ff e9                        bl 0x0
-; CHECKRELOC32-NEXT:    00000018:  R_RBR        (idx: 1) .memset[PR]
-; CHECKRELOC64-NEXT:    0000000000000018:  R_RBR	(idx: 1) .memset[PR]
+; CHECKRELOC32-NEXT:    00000018:  R_RBR        (idx: 1) .___memset[PR]
+; CHECKRELOC64-NEXT:    0000000000000018:  R_RBR	(idx: 1) .___memset64[PR]
diff --git a/llvm/test/CodeGen/PowerPC/aix-user-defined-memcpy.ll b/llvm/test/CodeGen/PowerPC/aix-user-defined-memcpy.ll
--- a/llvm/test/CodeGen/PowerPC/aix-user-defined-memcpy.ll
+++ b/llvm/test/CodeGen/PowerPC/aix-user-defined-memcpy.ll
@@ -38,6 +38,25 @@
 
 ; CHECK-NOT: .extern .memcpy
 
+; 32-SYM:      Symbol {{[{][[:space:]] *}}Index: [[#Index:]]{{[[:space:]] *}}Name: .___memmove
+; 32-SYM-NEXT:    Value (RelocatableAddress): 0x0
+; 32-SYM-NEXT:    Section: N_UNDEF
+; 32-SYM-NEXT:    Type: 0x0
+; 32-SYM-NEXT:    StorageClass: C_EXT (0x2)
+; 32-SYM-NEXT:    NumberOfAuxEntries: 1
+; 32-SYM-NEXT:    CSECT Auxiliary Entry {
+; 32-SYM-NEXT:      Index: 2
+; 32-SYM-NEXT:      SectionLen: 0
+; 32-SYM-NEXT:      ParameterHashIndex: 0x0
+; 32-SYM-NEXT:      TypeChkSectNum: 0x0
+; 32-SYM-NEXT:      SymbolAlignmentLog2: 0
+; 32-SYM-NEXT:      SymbolType: XTY_ER (0x0)
+; 32-SYM-NEXT:      StorageMappingClass: XMC_PR (0x0)
+; 32-SYM-NEXT:      StabInfoIndex: 0x0
+; 32-SYM-NEXT:      StabSectNum: 0x0
+; 32-SYM-NEXT:    }
+; 32-SYM-NEXT:  }
+
 ; 32-SYM:      Symbol {{[{][[:space:]] *}}Index: [[#Index:]]{{[[:space:]] *}}Name: .memcpy 
 ; 32-SYM-NEXT:    Value (RelocatableAddress): 0x0
 ; 32-SYM-NEXT:    Section: .text
@@ -45,8 +64,8 @@
 ; 32-SYM-NEXT:    StorageClass: C_EXT (0x2)
 ; 32-SYM-NEXT:    NumberOfAuxEntries: 1
 ; 32-SYM-NEXT:    CSECT Auxiliary Entry {
-; 32-SYM-NEXT:      Index: 4
-; 32-SYM-NEXT:      ContainingCsectSymbolIndex: 1
+; 32-SYM-NEXT:      Index: 6
+; 32-SYM-NEXT:      ContainingCsectSymbolIndex: 3
 ; 32-SYM-NEXT:      ParameterHashIndex: 0x0
 ; 32-SYM-NEXT:      TypeChkSectNum: 0x0
 ; 32-SYM-NEXT:      SymbolAlignmentLog2: 0
@@ -60,10 +79,20 @@
 ; 32-SYM-NOT: .memcpy
 
 ; 32-REL:      Relocations [
+; 32-REL-NEXT:  Section (index: 1) .text {
+; 32-REL-NEXT:  Relocation {
+; 32-REL-NEXT:    Virtual Address: 0x1C
+; 32-REL-NEXT:    Symbol: .___memmove (1)
+; 32-REL-NEXT:    IsSigned: Yes
+; 32-REL-NEXT:    FixupBitValue: 0
+; 32-REL-NEXT:    Length: 26
+; 32-REL-NEXT:    Type: R_RBR (0x1A)
+; 32-REL-NEXT:  }
+; 32-REL-NEXT:}
 ; 32-REL-NEXT:  Section (index: 2) .data {
 ; 32-REL-NEXT:  Relocation {
 ; 32-REL-NEXT:    Virtual Address: 0x34
-; 32-REL-NEXT:    Symbol: .memcpy (3)
+; 32-REL-NEXT:    Symbol: .memcpy (5)
 ; 32-REL-NEXT:    IsSigned: No
 ; 32-REL-NEXT:    FixupBitValue: 0
 ; 32-REL-NEXT:    Length: 32
@@ -71,7 +100,7 @@
 ; 32-REL-NEXT:  }
 ; 32-REL-NEXT:  Relocation {
 ; 32-REL-NEXT:    Virtual Address: 0x38
-; 32-REL-NEXT:    Symbol: TOC (11)
+; 32-REL-NEXT:    Symbol: TOC (13)
 ; 32-REL-NEXT:    IsSigned: No
 ; 32-REL-NEXT:    FixupBitValue: 0
 ; 32-REL-NEXT:    Length: 32
@@ -79,7 +108,7 @@
 ; 32-REL-NEXT:  }
 ; 32-REL-NEXT:  Relocation {
 ; 32-REL-NEXT:    Virtual Address: 0x40
-; 32-REL-NEXT:    Symbol: .call_memcpy (5)
+; 32-REL-NEXT:    Symbol: .call_memcpy (7)
 ; 32-REL-NEXT:    IsSigned: No
 ; 32-REL-NEXT:    FixupBitValue: 0
 ; 32-REL-NEXT:    Length: 32
@@ -87,7 +116,7 @@
 ; 32-REL-NEXT:  }
 ; 32-REL-NEXT:  Relocation {
 ; 32-REL-NEXT:    Virtual Address: 0x44
-; 32-REL-NEXT:    Symbol: TOC (11)
+; 32-REL-NEXT:    Symbol: TOC (13)
 ; 32-REL-NEXT:    IsSigned: No
 ; 32-REL-NEXT:    FixupBitValue: 0
 ; 32-REL-NEXT:    Length: 32