libstdc++: Improve test codegen for interpreting assembly
authorMatthias Kretz <kretz@kde.org>
Wed, 3 Feb 2021 15:49:30 +0000 (15:49 +0000)
committerJonathan Wakely <jwakely@redhat.com>
Wed, 3 Feb 2021 15:49:30 +0000 (15:49 +0000)
In many failure cases it is helpful to inspect the instructions leading
up to the test failure. After this change the location is easier to find
and the branch after failure is easier to find.

libstdc++-v3/ChangeLog:

* testsuite/experimental/simd/tests/bits/verify.h (verify): Add
instruction pointer data member. Ensure that the `if (m_failed)`
branch is always inlined into the calling code. The body of the
conditional can still be a function call. Move the get_ip call
into the verify ctor to simplify the ctor calls.
(COMPARE): Don't mention the use of all_of for reduction of a
simd_mask. It only distracts from the real issue.

libstdc++-v3/testsuite/experimental/simd/tests/bits/verify.h

index 826cfc34b5f3cf6680af54f16eca7deb6b2ad487..82016c66802953222782f251adaedb628c80a710 100644 (file)
@@ -60,6 +60,7 @@ template <class T>
 class verify
 {
   const bool m_failed = false;
+  size_t m_ip = 0;
 
   template <typename T,
            typename = decltype(std::declval<std::stringstream&>()
@@ -129,20 +130,21 @@ class verify
 
 public:
   template <typename... Ts>
-    verify(bool ok, size_t ip, const char* file, const int line,
+    [[gnu::always_inline]]
+    verify(bool ok, const char* file, const int line,
           const char* func, const char* cond, const Ts&... extra_info)
-    : m_failed(!ok)
+    : m_failed(!ok), m_ip(get_ip())
     {
       if (m_failed)
-       {
+       [&] {
          __builtin_fprintf(stderr, "%s:%d: (%s):\nInstruction Pointer: %x\n"
                                    "Assertion '%s' failed.\n",
-                           file, line, func, ip, cond);
+                           file, line, func, m_ip, cond);
          (print(extra_info, int()), ...);
-       }
+       }();
     }
 
-  ~verify()
+  [[gnu::always_inline]] ~verify()
   {
     if (m_failed)
       {
@@ -152,26 +154,27 @@ public:
   }
 
   template <typename T>
+    [[gnu::always_inline]]
     const verify&
     operator<<(const T& x) const
     {
       if (m_failed)
-       {
-         print(x, int());
-       }
+       print(x, int());
       return *this;
     }
 
   template <typename... Ts>
+    [[gnu::always_inline]]
     const verify&
     on_failure(const Ts&... xs) const
     {
       if (m_failed)
-       (print(xs, int()), ...);
+       [&] { (print(xs, int()), ...); }();
       return *this;
     }
 
-  [[gnu::always_inline]] static inline size_t
+  [[gnu::always_inline]] static inline
+  size_t
   get_ip()
   {
     size_t _ip = 0;
@@ -220,24 +223,21 @@ template <typename T>
 
 #define COMPARE(_a, _b)                                                        \
   [&](auto&& _aa, auto&& _bb) {                                                \
-    return verify(std::experimental::all_of(_aa == _bb), verify::get_ip(),     \
-                 __FILE__, __LINE__, __PRETTY_FUNCTION__,                     \
-                 "all_of(" #_a " == " #_b ")", #_a " = ", _aa,                \
+    return verify(std::experimental::all_of(_aa == _bb), __FILE__, __LINE__,   \
+                 __PRETTY_FUNCTION__, #_a " == " #_b, #_a " = ", _aa,         \
                  "\n" #_b " = ", _bb);                                        \
   }(force_fp_truncation(_a), force_fp_truncation(_b))
 #else
 #define COMPARE(_a, _b)                                                        \
   [&](auto&& _aa, auto&& _bb) {                                                \
-    return verify(std::experimental::all_of(_aa == _bb), verify::get_ip(),     \
-                 __FILE__, __LINE__, __PRETTY_FUNCTION__,                     \
-                 "all_of(" #_a " == " #_b ")", #_a " = ", _aa,                \
+    return verify(std::experimental::all_of(_aa == _bb), __FILE__, __LINE__,   \
+                 __PRETTY_FUNCTION__, #_a " == " #_b, #_a " = ", _aa,         \
                  "\n" #_b " = ", _bb);                                        \
   }((_a), (_b))
 #endif
 
 #define VERIFY(_test)                                                          \
-  verify(_test, verify::get_ip(), __FILE__, __LINE__, __PRETTY_FUNCTION__,     \
-        #_test)
+  verify(_test, __FILE__, __LINE__, __PRETTY_FUNCTION__, #_test)
 
   // ulp_distance_signed can raise FP exceptions and thus must be conditionally
   // executed
@@ -245,9 +245,9 @@ template <typename T>
   [&](auto&& _aa, auto&& _bb) {                                                \
     const bool success = std::experimental::all_of(                            \
       vir::test::ulp_distance(_aa, _bb) <= (_allowed_distance));               \
-    return verify(success, verify::get_ip(), __FILE__, __LINE__,               \
-                 __PRETTY_FUNCTION__, "all_of(" #_a " ~~ " #_b ")",           \
-                 #_a " = ", _aa, "\n" #_b " = ", _bb, "\ndistance = ",        \
+    return verify(success, __FILE__, __LINE__, __PRETTY_FUNCTION__,            \
+                 #_a " ~~ " #_b, #_a " = ", _aa, "\n" #_b " = ", _bb,         \
+                 "\ndistance = ",                                             \
                  success ? 0 : vir::test::ulp_distance_signed(_aa, _bb));     \
   }((_a), (_b))