diff --git a/builtins.go b/builtins.go
index 58589de7..2d43a8ed 100644
--- a/builtins.go
+++ b/builtins.go
@@ -5,133 +5,162 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strings"
 )
 
 // These are the GENERIC_SOURCES according to CMakeList.txt.
 var genericBuiltins = []string{
-	"absvdi2",
-	"absvsi2",
-	"absvti2",
-	"adddf3",
-	"addsf3",
-	"addtf3",
-	"addvdi3",
-	"addvsi3",
-	"addvti3",
-	"apple_versioning",
-	"ashldi3",
-	"ashlti3",
-	"ashrdi3",
-	"ashrti3",
-	"bswapdi2",
-	"bswapsi2",
-	"clzdi2",
-	"clzsi2",
-	"clzti2",
-	"cmpdi2",
-	"cmpti2",
-	"comparedf2",
-	"comparesf2",
-	"ctzdi2",
-	"ctzsi2",
-	"ctzti2",
-	"divdc3",
-	"divdf3",
-	"divdi3",
-	"divmoddi4",
-	"divmodsi4",
-	"divsc3",
-	"divsf3",
-	"divsi3",
-	"divtc3",
-	"divti3",
-	"divtf3",
-	"extendsfdf2",
-	"extendhfsf2",
-	"ffsdi2",
-	"ffssi2",
-	"ffsti2",
-	"fixdfdi",
-	"fixdfsi",
-	"fixdfti",
-	"fixsfdi",
-	"fixsfsi",
-	"fixsfti",
-	"fixunsdfdi",
-	"fixunsdfsi",
-	"fixunsdfti",
-	"fixunssfdi",
-	"fixunssfsi",
-	"fixunssfti",
-	"floatdidf",
-	"floatdisf",
-	"floatsidf",
-	"floatsisf",
-	"floattidf",
-	"floattisf",
-	"floatundidf",
-	"floatundisf",
-	"floatunsidf",
-	"floatunsisf",
-	"floatuntidf",
-	"floatuntisf",
-	//"int_util",
-	"lshrdi3",
-	"lshrti3",
-	"moddi3",
-	"modsi3",
-	"modti3",
-	"muldc3",
-	"muldf3",
-	"muldi3",
-	"mulodi4",
-	"mulosi4",
-	"muloti4",
-	"mulsc3",
-	"mulsf3",
-	"multi3",
-	"multf3",
-	"mulvdi3",
-	"mulvsi3",
-	"mulvti3",
-	"negdf2",
-	"negdi2",
-	"negsf2",
-	"negti2",
-	"negvdi2",
-	"negvsi2",
-	"negvti2",
-	"os_version_check",
-	"paritydi2",
-	"paritysi2",
-	"parityti2",
-	"popcountdi2",
-	"popcountsi2",
-	"popcountti2",
-	"powidf2",
-	"powisf2",
-	"powitf2",
-	"subdf3",
-	"subsf3",
-	"subvdi3",
-	"subvsi3",
-	"subvti3",
-	"subtf3",
-	"trampoline_setup",
-	"truncdfhf2",
-	"truncdfsf2",
-	"truncsfhf2",
-	"ucmpdi2",
-	"ucmpti2",
-	"udivdi3",
-	"udivmoddi4",
-	"udivmodsi4",
-	"udivmodti4",
-	"udivsi3",
-	"udivti3",
-	"umoddi3",
-	"umodsi3",
-	"umodti3",
+	"absvdi2.c",
+	"absvsi2.c",
+	"absvti2.c",
+	"adddf3.c",
+	"addsf3.c",
+	"addtf3.c",
+	"addvdi3.c",
+	"addvsi3.c",
+	"addvti3.c",
+	"apple_versioning.c",
+	"ashldi3.c",
+	"ashlti3.c",
+	"ashrdi3.c",
+	"ashrti3.c",
+	"bswapdi2.c",
+	"bswapsi2.c",
+	"clzdi2.c",
+	"clzsi2.c",
+	"clzti2.c",
+	"cmpdi2.c",
+	"cmpti2.c",
+	"comparedf2.c",
+	"comparesf2.c",
+	"ctzdi2.c",
+	"ctzsi2.c",
+	"ctzti2.c",
+	"divdc3.c",
+	"divdf3.c",
+	"divdi3.c",
+	"divmoddi4.c",
+	"divmodsi4.c",
+	"divsc3.c",
+	"divsf3.c",
+	"divsi3.c",
+	"divtc3.c",
+	"divti3.c",
+	"divtf3.c",
+	"extendsfdf2.c",
+	"extendhfsf2.c",
+	"ffsdi2.c",
+	"ffssi2.c",
+	"ffsti2.c",
+	"fixdfdi.c",
+	"fixdfsi.c",
+	"fixdfti.c",
+	"fixsfdi.c",
+	"fixsfsi.c",
+	"fixsfti.c",
+	"fixunsdfdi.c",
+	"fixunsdfsi.c",
+	"fixunsdfti.c",
+	"fixunssfdi.c",
+	"fixunssfsi.c",
+	"fixunssfti.c",
+	"floatdidf.c",
+	"floatdisf.c",
+	"floatsidf.c",
+	"floatsisf.c",
+	"floattidf.c",
+	"floattisf.c",
+	"floatundidf.c",
+	"floatundisf.c",
+	"floatunsidf.c",
+	"floatunsisf.c",
+	"floatuntidf.c",
+	"floatuntisf.c",
+	//"int_util.c",
+	"lshrdi3.c",
+	"lshrti3.c",
+	"moddi3.c",
+	"modsi3.c",
+	"modti3.c",
+	"muldc3.c",
+	"muldf3.c",
+	"muldi3.c",
+	"mulodi4.c",
+	"mulosi4.c",
+	"muloti4.c",
+	"mulsc3.c",
+	"mulsf3.c",
+	"multi3.c",
+	"multf3.c",
+	"mulvdi3.c",
+	"mulvsi3.c",
+	"mulvti3.c",
+	"negdf2.c",
+	"negdi2.c",
+	"negsf2.c",
+	"negti2.c",
+	"negvdi2.c",
+	"negvsi2.c",
+	"negvti2.c",
+	"os_version_check.c",
+	"paritydi2.c",
+	"paritysi2.c",
+	"parityti2.c",
+	"popcountdi2.c",
+	"popcountsi2.c",
+	"popcountti2.c",
+	"powidf2.c",
+	"powisf2.c",
+	"powitf2.c",
+	"subdf3.c",
+	"subsf3.c",
+	"subvdi3.c",
+	"subvsi3.c",
+	"subvti3.c",
+	"subtf3.c",
+	"trampoline_setup.c",
+	"truncdfhf2.c",
+	"truncdfsf2.c",
+	"truncsfhf2.c",
+	"ucmpdi2.c",
+	"ucmpti2.c",
+	"udivdi3.c",
+	"udivmoddi4.c",
+	"udivmodsi4.c",
+	"udivmodti4.c",
+	"udivsi3.c",
+	"udivti3.c",
+	"umoddi3.c",
+	"umodsi3.c",
+	"umodti3.c",
+}
+
+var aeabiBuiltins = []string{
+	"arm/aeabi_cdcmp.S",
+	"arm/aeabi_cdcmpeq_check_nan.c",
+	"arm/aeabi_cfcmp.S",
+	"arm/aeabi_cfcmpeq_check_nan.c",
+	"arm/aeabi_dcmp.S",
+	"arm/aeabi_div0.c",
+	"arm/aeabi_drsub.c",
+	"arm/aeabi_fcmp.S",
+	"arm/aeabi_frsub.c",
+	"arm/aeabi_idivmod.S",
+	"arm/aeabi_ldivmod.S",
+	"arm/aeabi_memcmp.S",
+	"arm/aeabi_memcpy.S",
+	"arm/aeabi_memmove.S",
+	"arm/aeabi_memset.S",
+	"arm/aeabi_uidivmod.S",
+	"arm/aeabi_uldivmod.S",
+}
+
+func builtinFiles(target string) []string {
+	builtins := append([]string{}, genericBuiltins...) // copy genericBuiltins
+	if target[:3] == "arm" {
+		builtins = append(builtins, aeabiBuiltins...)
+	}
+	return builtins
 }
 
 // Get the builtins archive, possibly generating it as needed.
@@ -139,9 +168,10 @@ func loadBuiltins(target string) (path string, err error) {
 	outfile := "librt-" + target + ".a"
 	builtinsDir := filepath.Join(sourceDir(), "lib", "compiler-rt", "lib", "builtins")
 
-	srcs := make([]string, len(genericBuiltins))
-	for i, name := range genericBuiltins {
-		srcs[i] = filepath.Join(builtinsDir, name+".c")
+	builtins := builtinFiles(target)
+	srcs := make([]string, len(builtins))
+	for i, name := range builtins {
+		srcs[i] = filepath.Join(builtinsDir, name)
 	}
 
 	if path, err := cacheLoad(outfile, commands["clang"], srcs); path != "" || err != nil {
@@ -156,11 +186,15 @@ func loadBuiltins(target string) (path string, err error) {
 
 	// Compile all builtins.
 	// TODO: use builtins optimized for a given target if available.
-	objs := make([]string, 0, len(genericBuiltins))
-	for _, name := range genericBuiltins {
-		objpath := filepath.Join(dir, name+".o")
+	objs := make([]string, 0, len(builtins))
+	for _, name := range builtins {
+		objname := name
+		if strings.LastIndexByte(objname, '/') >= 0 {
+			objname = objname[strings.LastIndexByte(objname, '/'):]
+		}
+		objpath := filepath.Join(dir, objname+".o")
 		objs = append(objs, objpath)
-		srcpath := filepath.Join(builtinsDir, name+".c")
+		srcpath := filepath.Join(builtinsDir, name)
 		cmd := exec.Command(commands["clang"], "-c", "-Oz", "-g", "-Werror", "-Wall", "-std=c11", "-fshort-enums", "-nostdlibinc", "--target="+target, "-o", objpath, srcpath)
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr