Merge pull request #756 from water111/w/u64-float-set

[goalc] support storing a float in a 64-bit memory location

docs/markdown/progress-notes/changelog.md

@@ -188,3 +188,4 @@
 - The register allocator has been dramatically improved and generates ~5x fewer spill instructions and is able to eliminate more moves.
 - Added a `(print-debug-compiler-stats)` form to print out statistics related to register allocation and move elimination
 - Added `get-enum-vals` which returns a list of pairs. Each pair is the name (symbol) and value (int) for each value in the enum
+- It is now possible to set a 64-bit memory location from a float, if you insert a cast. It will zero-extend the float, just like any other float -> 64-bit conversion.

goalc/compiler/compilation/Define.cpp

@@ -226,6 +226,7 @@ Val* Compiler::do_set(const goos::Object& form, Val* dest, RegVal* src_in_reg, V
       src_in_reg = src_128;
     }
 
+    // we want to allow setting a smaller thing from a 128-bit variable
     if (as_mem_deref->info.size != 16 && (src_in_reg->ireg().reg_class == RegClass::VECTOR_FLOAT ||
                                           src_in_reg->ireg().reg_class == RegClass::INT_128)) {
       auto fe = get_parent_env_of_type<FunctionEnv>(env);
@@ -234,6 +235,14 @@ Val* Compiler::do_set(const goos::Object& form, Val* dest, RegVal* src_in_reg, V
       src_in_reg = src_gpr;
     }
 
+    // we want to allow setting a 64-bit place to a float
+    if (as_mem_deref->info.size == 8 && src_in_reg->ireg().reg_class == RegClass::FLOAT) {
+      auto fe = get_parent_env_of_type<FunctionEnv>(env);
+      auto src_gpr = fe->make_ireg(src_in_reg->type(), RegClass::GPR_64);
+      env->emit_ir<IR_RegSet>(src_gpr, src_in_reg);
+      src_in_reg = src_gpr;
+    }
+
     // setting somewhere in memory
     auto base = as_mem_deref->base;
     auto base_as_mco = dynamic_cast<MemoryOffsetConstantVal*>(base);

test/goalc/source_templates/with_game/test-set-u64-from-float.gc

@@ -0,0 +1,8 @@
+(let ((a (new 'stack-no-clear 'array 'float 4))
+      (b (new 'stack-no-clear 'array 'uint64 2))
+      )
+  (set! (-> b 0) #xbbbbbbbbbbbbbbbb)
+  (set! (-> a 0) 12.0)
+  (set! (-> b 0) (the-as uint (- (-> a 0))))
+  (format #t "~f #x~X #x~X #x~X~%" (-> b 0) (-> b 0) (-> (the-as (pointer uint32) b) 0) (-> (the-as (pointer uint32) b) 1))
+  )

test/goalc/test_with_game.cpp

@@ -830,6 +830,11 @@ TEST_F(WithGameTests, GetEnumVals) {
                           "(thing5 . #<invalid object #x5>))\n0\n"});
 }
 
+TEST_F(WithGameTests, SetU64FromFloat) {
+  runner.run_static_test(env, testCategory, "test-set-u64-from-float.gc",
+                         {"-12.0000 #xc1400000 #xc1400000 #x0\n0\n"});
+}
+
 TEST(TypeConsistency, TypeConsistency) {
   Compiler compiler;
   compiler.enable_throw_on_redefines();