diff --git a/cgcc b/cgcc
index f3909ae89..a99a3a1c3 100755
--- a/cgcc
+++ b/cgcc
@@ -287,16 +287,16 @@ sub add_specs {
 	    " -D'__fastcall=__attribute__((__fastcall__))'" .
 	    " -D'__declspec(x)=__attribute__((x))'";
     } elsif ($spec eq 'i386') {
-	return (' -D__i386=1 -D__i386__=1' .
+	return (
 		&float_types (1, 1, 21, [24,8], [53,11], [64,15]));
     } elsif ($spec eq 'sparc') {
-	return (' -D__sparc=1 -D__sparc__=1' .
+	return (
 		&integer_types (8, 16, 32, $m64 ? 64 : 32, 64) .
 		&float_types (1, 1, 33, [24,8], [53,11], [113,15]) .
 		&define_size_t ($m64 ? "long unsigned int" : "unsigned int") .
 		' -D__SIZEOF_POINTER__=' . ($m64 ? '8' : '4'));
     } elsif ($spec eq 'sparc64') {
-	return (' -D__sparc=1 -D__sparc__=1 -D__sparcv9__=1 -D__sparc64__=1 -D__arch64__=1 -D__LP64__=1' .
+	return (
 		&integer_types (8, 16, 32, 64, 64, 128) .
 		&float_types (1, 1, 33, [24,8], [53,11], [113,15]) .
 		&define_size_t ("long unsigned int") .
@@ -304,25 +304,23 @@ sub add_specs {
     } elsif ($spec eq 'x86_64') {
 	return &float_types (1, 1, 33, [24,8], [53,11], [113,15]);
     } elsif ($spec eq 'ppc') {
-	return (' -D__powerpc__=1 -D_BIG_ENDIAN -D_STRING_ARCH_unaligned=1' .
+	return (' -D_BIG_ENDIAN -D_STRING_ARCH_unaligned=1' .
 		&integer_types (8, 16, 32, $m64 ? 64 : 32, 64) .
 		&float_types (1, 1, 21, [24,8], [53,11], [113,15]) .
 		&define_size_t ($m64 ? "long unsigned int" : "unsigned int") .
 		' -D__SIZEOF_POINTER__=' . ($m64 ? '8' : '4'));
     } elsif ($spec eq 'ppc64') {
-	return (' -D__powerpc__=1 -D__PPC__=1 -D_STRING_ARCH_unaligned=1' .
-		' -D__powerpc64__=1 -D__PPC64__=1' .
-		' -m64' .
+	return (' -D_STRING_ARCH_unaligned=1 -m64' .
 		&float_types (1, 1, 21, [24,8], [53,11], [113,15]));
     } elsif ($spec eq 's390x') {
-	return (' -D__s390x__ -D__s390__ -D_BIG_ENDIAN' .
+	return (' -D_BIG_ENDIAN' .
 		&integer_types (8, 16, 32, $m64 ? 64 : 32, 64) .
 		&float_types (1, 1, 36, [24,8], [53,11], [113,15]) .
 		&define_size_t ("long unsigned int") .
 		' -D__SIZEOF_POINTER__=' . ($m64 ? '8' : '4'));
     } elsif ($spec eq 'arm') {
 	chomp (my $gccmachine = `$cc -dumpmachine`);
-	my $cppsymbols = ' -D__arm__=1 -m32';
+	my $cppsymbols = ' -m32';
 
 	if ($gccmachine eq 'arm-linux-gnueabihf') {
 	    $cppsymbols .= ' -D__ARM_PCS_VFP=1';
@@ -331,7 +329,7 @@ sub add_specs {
 	return ($cppsymbols .
 		&float_types (1, 1, 36, [24,8], [53,11], [53, 11]));
     } elsif ($spec eq 'aarch64') {
-	return (' -D__aarch64__=1 -m64' .
+	return (' -m64' .
 		&float_types (1, 1, 36, [24,8], [53,11], [113,15]));
     } elsif ($spec eq 'host_os_specs') {
 	my $os = `uname -s`;
diff --git a/lib.c b/lib.c
index 60fc33496..91d347109 100644
--- a/lib.c
+++ b/lib.c
@@ -1364,20 +1364,73 @@ static void predefined_macros(void)
 		break;
 	}
 
-	if (arch_m64 != ARCH_LP32) {
-#if defined(__x86_64__) || defined(__x86_64)
-		predefine("__x86_64__", 1, "1");
-		predefine("__x86_64", 1, "1");
-#endif
-	}
-
 	switch (arch_mach) {
+	case MACH_ARM64:
+		predefine("__aarch64__", 1, "1");
+		break;
+	case MACH_ARM:
+		predefine("__arm__", 1, "1");
+		break;
+	case MACH_M68K:
+		predefine("__m68k__", 1, "1");
+		break;
 	case MACH_MIPS64:
+		if (arch_m64 == ARCH_LP64)
+			predefine("__mips64", 1, "64");
+		/* fall-through */
 	case MACH_MIPS32:
+		predefine("__mips", 1, "%d", ptr_ctype.bit_size);
 		predefine("_MIPS_SZINT", 1, "%d", int_ctype.bit_size);
 		predefine("_MIPS_SZLONG", 1, "%d", long_ctype.bit_size);
 		predefine("_MIPS_SZPTR", 1, "%d", ptr_ctype.bit_size);
 		break;
+	case MACH_PPC64:
+		if (arch_m64 == ARCH_LP64) {
+			predefine("__powerpc64__", 1, "1");
+			predefine("__ppc64__", 1, "1");
+			predefine("__PPC64__", 1, "1");
+		}
+		/* fall-through */
+	case MACH_PPC32:
+		predefine("__powerpc__", 1, "1");
+		predefine("__powerpc", 1, "1");
+		predefine("__ppc__", 1, "1");
+		predefine("__PPC__", 1, "1");
+		break;
+	case MACH_RISCV64:
+	case MACH_RISCV32:
+		predefine("__riscv", 1, "1");
+		predefine("__riscv_xlen", 1, "%d", ptr_ctype.bit_size);
+		break;
+	case MACH_S390X:
+		predefine("__zarch__", 1, "1");
+		predefine("__s390x__", 1, "1");
+		predefine("__s390__", 1, "1");
+		break;
+	case MACH_SPARC64:
+		if (arch_m64 == ARCH_LP64) {
+			predefine("__sparc_v9__", 1, "1");
+			predefine("__sparcv9__", 1, "1");
+			predefine("__sparcv9", 1, "1");
+			predefine("__sparc64__", 1, "1");
+			predefine("__arch64__", 1, "1");
+		}
+		/* fall-through */
+	case MACH_SPARC32:
+		predefine("__sparc__", 1, "1");
+		predefine("__sparc", 1, "1");
+		break;
+	case MACH_X86_64:
+		if (arch_m64 != ARCH_LP32) {
+			predefine("__x86_64__", 1, "1");
+			predefine("__x86_64", 1, "1");
+			break;
+		}
+		/* fall-through */
+	case MACH_I386:
+		predefine("__i386__", 1, "1");
+		predefine("__i386", 1, "1");
+		break;
 	}
 }
 
