Emit jumps rather than stores for conditions

mockingbirdnest · Jan 6, 2025 · ac924ce · ac924ce
1 parent 8c5eb1e
commit ac924ce
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Showing 2 changed files with 19 additions and 13 deletions.
diff --git a/geometry/hilbert_body.hpp b/geometry/hilbert_body.hpp
@@ -48,7 +48,8 @@ auto Hilbert<T, T>::Norm(T const& t) -> NormType {
       _MSC_FULL_VER == 193'933'523 || \
       _MSC_FULL_VER == 194'033'813 || \
       _MSC_FULL_VER == 194'134'120 || \
-      _MSC_FULL_VER == 194'134'123)
+      _MSC_FULL_VER == 194'134'123 || \
+      _MSC_FULL_VER == 194'234'435)
 template<typename T1, typename T2>
   requires hilbert<T1, T2>
 auto Hilbert<T1, T2>::InnerProduct(T1 const& t1, T2 const& t2)

diff --git a/numerics/osaca.hpp b/numerics/osaca.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#define PRINCIPIA_USE_OSACA 0
+#define PRINCIPIA_USE_OSACA 1
 
 // The macros OSACA_FUNCTION_BEGIN and OSACA_RETURN are used to analyse the
 // latency of a double -> double function, as measured, e.g., by the
@@ -175,21 +175,26 @@ static bool volatile OSACA_loop_terminator = false;
 
 // The branch not taken, determined by evaluating the condition
 // `UNDER_OSACA_HYPOTHESES`, is eliminated by `if constexpr`; the condition is
-// also compiled normally and assigned to a boolean; whether this results in any
-// generated code depends on `OSACA_EVALUATE_CONDITIONS`.  Note that, with
-// `OSACA_EVALUATE_CONDITIONS`, in  `OSACA_IF(p) { } OSACA_ELSE_IF(q) { }`, if
-// `p` holds `UNDER_OSACA_HYPOTHESES`, code is generated to evaluate `p`, but
-// not `q`.
-
-#define OSACA_IF(condition)                                               \
-  if constexpr (bool OSACA_CONDITION_QUALIFIER OSACA_computed_condition = \
-                    (condition);                                          \
+// also compiled normally.  Whether this results in any generated code depends
+// on `OSACA_EVALUATE_CONDITIONS`.  Note that, with `OSACA_EVALUATE_CONDITIONS`,
+// in `OSACA_IF(p) { } OSACA_ELSE_IF(q) { }`, if  `p` holds
+// `UNDER_OSACA_HYPOTHESES`, code is generated to evaluate `p`, but  not `q`.
+
+#define OSACA_IF(condition)                                             \
+  if constexpr (int const OSACA_evaluate =                              \
+                    UNDER_OSACA_HYPOTHESES(condition)                   \
+                        ? ((condition) ? 0 : OSACA_branch_not_taken())  \
+                        : ((condition) ? OSACA_branch_not_taken() : 0); \
                 UNDER_OSACA_HYPOTHESES(condition))
 
 #if OSACA_EVALUATE_CONDITIONS
-#define OSACA_CONDITION_QUALIFIER volatile
+[[noreturn]] inline int OSACA_branch_not_taken() {
+  std::abort();
+}
 #else
-#define OSACA_CONDITION_QUALIFIER
+inline int OSACA_branch_not_taken() {
+  return 0;
+}
 #endif
 
 #else  // if !PRINCIPIA_USE_OSACA