MIPS: Improve runtime detection and compatibility wrt arch. revisions.

build/toolchain.gypi

Index: build/toolchain.gypi
diff --git a/build/toolchain.gypi b/build/toolchain.gypi
index b04f661d8571623cb634df3a5a7736ed0fa804ec..a7410754598e3a70299e10e11875c8315beb7a75 100644
--- a/build/toolchain.gypi
+++ b/build/toolchain.gypi
@@ -302,7 +302,7 @@
                     'cflags': ['-mfp32'],
                   }],
                   ['mips_arch_variant=="r6"', {
-                    'cflags!': ['-mfp32'],
+                    'cflags!': ['-mfp32', '-mfpxx'],
                     'cflags': ['-mips32r6', '-Wa,-mips32r6'],
                     'ldflags': [
                       '-mips32r6',
@@ -312,14 +312,17 @@
                   }],
                   ['mips_arch_variant=="r2"', {
                     'cflags': ['-mips32r2', '-Wa,-mips32r2'],
+                    'ldflags': ['-mips32r2'],
                   }],
                   ['mips_arch_variant=="r1"', {
-                    'cflags!': ['-mfp64'],
+                    'cflags!': ['-mfp64', '-mfpxx'],
                     'cflags': ['-mips32', '-Wa,-mips32'],
+                    'ldflags': ['-mips32'],
                   }],
                   ['mips_arch_variant=="rx"', {
-                    'cflags!': ['-mfp64'],
-                    'cflags': ['-mips32', '-Wa,-mips32'],
+                    'cflags!': ['-mfp64', '-mfp32'],
+                    'cflags': ['-mips32', '-Wa,-mips32', '-mfpxx'],
+                    'ldflags': ['-mips32'],
                   }],
                 ],
               }],
@@ -400,7 +403,7 @@
                     'cflags': ['-mfp32'],
                   }],
                   ['mips_arch_variant=="r6"', {
-                    'cflags!': ['-mfp32'],
+                    'cflags!': ['-mfp32', '-mfpxx'],
                     'cflags': ['-mips32r6', '-Wa,-mips32r6'],
                     'ldflags': [
                       '-mips32r6',
@@ -410,17 +413,20 @@
                   }],
                   ['mips_arch_variant=="r2"', {
                     'cflags': ['-mips32r2', '-Wa,-mips32r2'],
+                    'ldflags': ['-mips32r2'],
                   }],
                   ['mips_arch_variant=="r1"', {
-                    'cflags!': ['-mfp64'],
+                    'cflags!': ['-mfp64', '-mfpxx'],
                     'cflags': ['-mips32', '-Wa,-mips32'],
+                    'ldflags': ['-mips32'],
                   }],
                   ['mips_arch_variant=="rx"', {
-                    'cflags!': ['-mfp64'],
-                    'cflags': ['-mips32', '-Wa,-mips32'],
+                    'cflags!': ['-mfp64', '-mfp32'],
+                    'cflags': ['-mips32', '-Wa,-mips32', '-mfpxx'],
+                    'ldflags': ['-mips32'],
                   }],
                   ['mips_arch_variant=="loongson"', {
-                    'cflags!': ['-mfp64'],
+                    'cflags!': ['-mfp64', '-mfp32', '-mfpxx'],
                     'cflags': ['-mips3', '-Wa,-mips3'],
                   }],
                 ],