--- src/build-data/cc/clang.txt
+++ src/build-data/cc/clang.txt
@@ -76,10 +76,11 @@ all!haiku,llvm -> "-pthread"
 
 openmp  -> "-fopenmp"
 
-x86_32  -> "-m32"
-x86_64  -> "-m64"
-ppc64   -> "-m64"
+x86_32  -> "-arch i386"
+x86_64  -> "-arch x86_64"
+ppc32   -> "-arch ppc"
+ppc64   -> "-arch ppc64"
 
-macos   -> "-stdlib=libc++"
+macos   -> "-stdlib=__MACPORTS_CXX_STDLIB__"
 ios     -> "-stdlib=libc++"
 </mach_abi_linking>
--- src/build-data/cc/gcc.txt
+++ src/build-data/cc/gcc.txt
@@ -89,9 +89,10 @@ s390    -> "-m31"
 s390x   -> "-m64"
 sparc32 -> "-m32 -mno-app-regs"
 sparc64 -> "-m64 -mno-app-regs"
-ppc64   -> "-m64"
-x86_32  -> "-m32"
-x86_64  -> "-m64"
+ppc32   -> "-arch ppc"
+ppc64   -> "-arch ppc64"
+x86_32  -> "-arch i386"
+x86_64  -> "-arch x86_64"
 x32     -> "-mx32"
 
 qnx     -> "-fexceptions"