fix nim-lang#12884 VM float32

timotheecour · Dec 16, 2019 · 6aae864 · 6aae864
1 parent e5ed4c1
commit 6aae864
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Showing 3 changed files with 32 additions and 3 deletions.
diff --git a/compiler/vm.nim b/compiler/vm.nim
@@ -252,7 +252,10 @@ proc putIntoReg(dest: var TFullReg; n: PNode) =
     dest.intVal = n.intVal
   of nkFloatLit..nkFloat128Lit:
     dest.kind = rkFloat
-    dest.floatVal = n.floatVal
+    case n.typ.kind
+    of tyFloat32: dest.floatVal = n.floatVal.float32
+    of tyFloat: dest.floatVal = n.floatVal.float # handles 32bit float on 32 bit platforms
+    else: dest.floatVal = n.floatVal
   else:
     dest.kind = rkNode
     dest.node = n

diff --git a/compiler/vmgen.nim b/compiler/vmgen.nim
@@ -451,7 +451,8 @@ proc sameConstant*(a, b: PNode): bool =
     of nkSym: result = a.sym == b.sym
     of nkIdent: result = a.ident.id == b.ident.id
     of nkCharLit..nkUInt64Lit: result = a.intVal == b.intVal
-    of nkFloatLit..nkFloat64Lit: result = a.floatVal == b.floatVal
+    of nkFloatLit..nkFloat64Lit:
+      result = a.floatVal == b.floatVal and a.typ.kind == b.typ.kind
     of nkStrLit..nkTripleStrLit: result = a.strVal == b.strVal
     of nkType, nkNilLit: result = a.typ == b.typ
     of nkEmpty: result = true
@@ -462,7 +463,7 @@ proc sameConstant*(a, b: PNode): bool =
         result = true
 
 proc genLiteral(c: PCtx; n: PNode): int =
-  # types do not matter here:
+  # types do not matter here except for special cases eg float32, see #12884
   for i in 0..<c.constants.len:
     if sameConstant(c.constants[i], n): return i
   result = rawGenLiteral(c, n)

diff --git a/tests/vm/tfloat32.nim b/tests/vm/tfloat32.nim
@@ -0,0 +1,25 @@
+proc main(): string =
+  let x0 = float32(1.32)
+  let x1: float32 = 1.32
+  let x3 = 1.32'f32
+  let x4 = 1.32
+  let x2 = x1
+  let x5 = x3*x3 # will differ here
+  let x6 = 1.32'f64
+  let x7: float = 1.32
+  $(x0, x1, x2, x3, x4, x5, x6, x7, x3*x3,
+    x3 * 2.0,  # will differ here
+     $type(x4), $type(x5))
+
+const a1 = main()
+let a2 = main()
+
+#[
+CT (a1) and RT (a2) values differ when float operations are involved (eg x3*x3),
+but otherwise are the same
+]#
+doAssert a1 == """
+(1.320000052452087, 1.320000052452087, 1.320000052452087, 1.320000052452087, 1.32, 1.742400138473513, 1.32, 1.32, 1.742400138473513, 2.640000104904175, "float64", "float32")"""
+
+doAssert a2 == """
+(1.320000052452087, 1.320000052452087, 1.320000052452087, 1.320000052452087, 1.32, 1.742400169372559, 1.32, 1.32, 1.742400169372559, 2.640000104904175, "float64", "float32")"""