powerpc/math-emu: Update macros from GCC

The add_ssaaaa, sub_ddmmss, umul_ppmm and udiv_qrnnd macros originate
from GCC's longlong.h which in turn was copied from GMP's longlong.h a
few decades ago.

This was found when compiling with clang:

   arch/powerpc/math-emu/fnmsub.c:46:2: error: invalid use of a cast in a
   inline asm context requiring an l-value: remove the cast or build with
   -fheinous-gnu-extensions
           FP_ADD_D(R, T, B);
           ^~~~~~~~~~~~~~~~~
   ...

   ./arch/powerpc/include/asm/sfp-machine.h:283:27: note: expanded from
   macro 'sub_ddmmss'
                  : "=r" ((USItype)(sh)),                                  \
                          ~~~~~~~~~~^~~

Segher points out: this was fixed in GCC over 16 years ago
( https://gcc.gnu.org/r56600 ), and in GMP (where it comes from)
presumably before that.

Update the add_ssaaaa, sub_ddmmss, umul_ppmm and udiv_qrnnd macros to
the latest GCC version in order to git rid of the invalid casts. These
were taken as-is from GCC's longlong in order to make future syncs
obvious. Other parts of sfp-machine.h were left as-is as the file
contains more features than present in longlong.h.

Link: https://github.com/ClangBuiltLinux/linux/issues/260
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/include/asm/sfp-machine.h b/arch/powerpc/include/asm/sfp-machine.h
index d89beaba26ff95d2ab0ed48cdaf1ba7fc8f3bd73..8b957aabb826d3b55674cab70e3fc096869f8ec0 100644 (file)
--- a/arch/powerpc/include/asm/sfp-machine.h
+++ b/arch/powerpc/include/asm/sfp-machine.h
@@ -213,30 +213,18 @@
  * respectively.  The result is placed in HIGH_SUM and LOW_SUM.  Overflow
  * (i.e. carry out) is not stored anywhere, and is lost.
  */
-#define add_ssaaaa(sh, sl, ah, al, bh, bl)                             \
+#define add_ssaaaa(sh, sl, ah, al, bh, bl) \
   do {                                                                 \
     if (__builtin_constant_p (bh) && (bh) == 0)                                \
-      __asm__ ("{a%I4|add%I4c} %1,%3,%4\n\t{aze|addze} %0,%2"          \
-            : "=r" ((USItype)(sh)),                                    \
-              "=&r" ((USItype)(sl))                                    \
-            : "%r" ((USItype)(ah)),                                    \
-              "%r" ((USItype)(al)),                                    \
-              "rI" ((USItype)(bl)));                                   \
-    else if (__builtin_constant_p (bh) && (bh) ==~(USItype) 0)         \
-      __asm__ ("{a%I4|add%I4c} %1,%3,%4\n\t{ame|addme} %0,%2"          \
-            : "=r" ((USItype)(sh)),                                    \
-              "=&r" ((USItype)(sl))                                    \
-            : "%r" ((USItype)(ah)),                                    \
-              "%r" ((USItype)(al)),                                    \
-              "rI" ((USItype)(bl)));                                   \
+      __asm__ ("add%I4c %1,%3,%4\n\taddze %0,%2"               \
+            : "=r" (sh), "=&r" (sl) : "r" (ah), "%r" (al), "rI" (bl));\
+    else if (__builtin_constant_p (bh) && (bh) == ~(USItype) 0)                \
+      __asm__ ("add%I4c %1,%3,%4\n\taddme %0,%2"               \
+            : "=r" (sh), "=&r" (sl) : "r" (ah), "%r" (al), "rI" (bl));\
     else                                                               \
-      __asm__ ("{a%I5|add%I5c} %1,%4,%5\n\t{ae|adde} %0,%2,%3"         \
-            : "=r" ((USItype)(sh)),                                    \
-              "=&r" ((USItype)(sl))                                    \
-            : "%r" ((USItype)(ah)),                                    \
-              "r" ((USItype)(bh)),                                     \
-              "%r" ((USItype)(al)),                                    \
-              "rI" ((USItype)(bl)));                                   \
+      __asm__ ("add%I5c %1,%4,%5\n\tadde %0,%2,%3"             \
+            : "=r" (sh), "=&r" (sl)                                    \
+            : "%r" (ah), "r" (bh), "%r" (al), "rI" (bl));              \
   } while (0)
 
 /* sub_ddmmss is used in op-2.h and udivmodti4.c and should be equivalent to
@@ -248,44 +236,24 @@
  * and LOW_DIFFERENCE.  Overflow (i.e. carry out) is not stored anywhere,
  * and is lost.
  */
-#define sub_ddmmss(sh, sl, ah, al, bh, bl)                             \
+#define sub_ddmmss(sh, sl, ah, al, bh, bl) \
   do {                                                                 \
     if (__builtin_constant_p (ah) && (ah) == 0)                                \
-      __asm__ ("{sf%I3|subf%I3c} %1,%4,%3\n\t{sfze|subfze} %0,%2"      \
-              : "=r" ((USItype)(sh)),                                  \
-                "=&r" ((USItype)(sl))                                  \
-              : "r" ((USItype)(bh)),                                   \
-                "rI" ((USItype)(al)),                                  \
-                "r" ((USItype)(bl)));                                  \
-    else if (__builtin_constant_p (ah) && (ah) ==~(USItype) 0)         \
-      __asm__ ("{sf%I3|subf%I3c} %1,%4,%3\n\t{sfme|subfme} %0,%2"      \
-              : "=r" ((USItype)(sh)),                                  \
-                "=&r" ((USItype)(sl))                                  \
-              : "r" ((USItype)(bh)),                                   \
-                "rI" ((USItype)(al)),                                  \
-                "r" ((USItype)(bl)));                                  \
+      __asm__ ("subf%I3c %1,%4,%3\n\tsubfze %0,%2"     \
+              : "=r" (sh), "=&r" (sl) : "r" (bh), "rI" (al), "r" (bl));\
+    else if (__builtin_constant_p (ah) && (ah) == ~(USItype) 0)                \
+      __asm__ ("subf%I3c %1,%4,%3\n\tsubfme %0,%2"     \
+              : "=r" (sh), "=&r" (sl) : "r" (bh), "rI" (al), "r" (bl));\
     else if (__builtin_constant_p (bh) && (bh) == 0)                   \
-      __asm__ ("{sf%I3|subf%I3c} %1,%4,%3\n\t{ame|addme} %0,%2"                \
-              : "=r" ((USItype)(sh)),                                  \
-                "=&r" ((USItype)(sl))                                  \
-              : "r" ((USItype)(ah)),                                   \
-                "rI" ((USItype)(al)),                                  \
-                "r" ((USItype)(bl)));                                  \
-    else if (__builtin_constant_p (bh) && (bh) ==~(USItype) 0)         \
-      __asm__ ("{sf%I3|subf%I3c} %1,%4,%3\n\t{aze|addze} %0,%2"                \
-              : "=r" ((USItype)(sh)),                                  \
-                "=&r" ((USItype)(sl))                                  \
-              : "r" ((USItype)(ah)),                                   \
-                "rI" ((USItype)(al)),                                  \
-                "r" ((USItype)(bl)));                                  \
+      __asm__ ("subf%I3c %1,%4,%3\n\taddme %0,%2"              \
+              : "=r" (sh), "=&r" (sl) : "r" (ah), "rI" (al), "r" (bl));\
+    else if (__builtin_constant_p (bh) && (bh) == ~(USItype) 0)                \
+      __asm__ ("subf%I3c %1,%4,%3\n\taddze %0,%2"              \
+              : "=r" (sh), "=&r" (sl) : "r" (ah), "rI" (al), "r" (bl));\
     else                                                               \
-      __asm__ ("{sf%I4|subf%I4c} %1,%5,%4\n\t{sfe|subfe} %0,%3,%2"     \
-              : "=r" ((USItype)(sh)),                                  \
-                "=&r" ((USItype)(sl))                                  \
-              : "r" ((USItype)(ah)),                                   \
-                "r" ((USItype)(bh)),                                   \
-                "rI" ((USItype)(al)),                                  \
-                "r" ((USItype)(bl)));                                  \
+      __asm__ ("subf%I4c %1,%5,%4\n\tsubfe %0,%3,%2"   \
+              : "=r" (sh), "=&r" (sl)                                  \
+              : "r" (ah), "r" (bh), "rI" (al), "r" (bl));              \
   } while (0)
 
 /* asm fragments for mul and div */
@@ -294,13 +262,10 @@
  * UWtype integers MULTIPLER and MULTIPLICAND, and generates a two UWtype
  * word product in HIGH_PROD and LOW_PROD.
  */
-#define umul_ppmm(ph, pl, m0, m1)                                      \
+#define umul_ppmm(ph, pl, m0, m1) \
   do {                                                                 \
     USItype __m0 = (m0), __m1 = (m1);                                  \
-    __asm__ ("mulhwu %0,%1,%2"                                         \
-            : "=r" ((USItype)(ph))                                     \
-            : "%r" (__m0),                                             \
-               "r" (__m1));                                            \
+    __asm__ ("mulhwu %0,%1,%2" : "=r" (ph) : "%r" (m0), "r" (m1));     \
     (pl) = __m0 * __m1;                                                        \
   } while (0)
 
@@ -312,9 +277,10 @@
  * significant bit of DENOMINATOR must be 1, then the pre-processor symbol
  * UDIV_NEEDS_NORMALIZATION is defined to 1.
  */
-#define udiv_qrnnd(q, r, n1, n0, d)                                    \
+#define udiv_qrnnd(q, r, n1, n0, d) \
   do {                                                                 \
-    UWtype __d1, __d0, __q1, __q0, __r1, __r0, __m;                    \
+    UWtype __d1, __d0, __q1, __q0;                                     \
+    UWtype __r1, __r0, __m;                                            \
     __d1 = __ll_highpart (d);                                          \
     __d0 = __ll_lowpart (d);                                           \
                                                                        \
@@ -325,7 +291,7 @@
     if (__r1 < __m)                                                    \
       {                                                                        \
        __q1--, __r1 += (d);                                            \
-       if (__r1 >= (d)) /* we didn't get carry when adding to __r1 */  \
+       if (__r1 >= (d)) /* i.e. we didn't get carry when adding to __r1 */\
          if (__r1 < __m)                                               \
            __q1--, __r1 += (d);                                        \
       }                                                                        \