NaN flip a sign bit on ARM(el)

[kapouer]

As can be seen in this build log

-[LoggingExternalInterface logging nan:0x7fff82]
+[LoggingExternalInterface logging -nan:0x7fff82]

The best I could find about this.

[kapouer]

In this diff I commented the places where a bunch of tests fail on armel:

--- a/test/spec/conversions.wast
+++ b/test/spec/conversions.wast
@@ -431,15 +431,15 @@
 (assert_return (invoke "f32.reinterpret_i32" (i32.const 0)) (f32.const 0.0))
 (assert_return (invoke "f32.reinterpret_i32" (i32.const 0x80000000)) (f32.const -0.0))
 (assert_return (invoke "f32.reinterpret_i32" (i32.const 1)) (f32.const 0x1p-149))
-(assert_return (invoke "f32.reinterpret_i32" (i32.const -1)) (f32.const -nan:0x7fffff))
+;;(assert_return (invoke "f32.reinterpret_i32" (i32.const -1)) (f32.const -nan:0x7fffff))
 (assert_return (invoke "f32.reinterpret_i32" (i32.const 123456789)) (f32.const 0x1.b79a2ap-113))
 (assert_return (invoke "f32.reinterpret_i32" (i32.const -2147483647)) (f32.const -0x1p-149))
 (assert_return (invoke "f32.reinterpret_i32" (i32.const 0x7f800000)) (f32.const inf))
 (assert_return (invoke "f32.reinterpret_i32" (i32.const 0xff800000)) (f32.const -inf))
 (assert_return (invoke "f32.reinterpret_i32" (i32.const 0x7fc00000)) (f32.const nan))
-(assert_return (invoke "f32.reinterpret_i32" (i32.const 0xffc00000)) (f32.const -nan))
+;;(assert_return (invoke "f32.reinterpret_i32" (i32.const 0xffc00000)) (f32.const -nan))
 (assert_return (invoke "f32.reinterpret_i32" (i32.const 0x7fa00000)) (f32.const nan:0x200000))
-(assert_return (invoke "f32.reinterpret_i32" (i32.const 0xffa00000)) (f32.const -nan:0x200000))
+;;(assert_return (invoke "f32.reinterpret_i32" (i32.const 0xffa00000)) (f32.const -nan:0x200000))
 
 (assert_return (invoke "f64.reinterpret_i64" (i64.const 0)) (f64.const 0.0))
 (assert_return (invoke "f64.reinterpret_i64" (i64.const 1)) (f64.const 0x0.0000000000001p-1022))
@@ -457,7 +457,7 @@
 (assert_return (invoke "i32.reinterpret_f32" (f32.const 0.0)) (i32.const 0))
 (assert_return (invoke "i32.reinterpret_f32" (f32.const -0.0)) (i32.const 0x80000000))
 (assert_return (invoke "i32.reinterpret_f32" (f32.const 0x1p-149)) (i32.const 1))
-(assert_return (invoke "i32.reinterpret_f32" (f32.const -nan:0x7fffff)) (i32.const -1))
+;;(assert_return (invoke "i32.reinterpret_f32" (f32.const -nan:0x7fffff)) (i32.const -1))
 (assert_return (invoke "i32.reinterpret_f32" (f32.const -0x1p-149)) (i32.const 0x80000001))
 (assert_return (invoke "i32.reinterpret_f32" (f32.const 1.0)) (i32.const 1065353216))
 (assert_return (invoke "i32.reinterpret_f32" (f32.const 3.1415926)) (i32.const 1078530010))
@@ -466,9 +466,9 @@
 (assert_return (invoke "i32.reinterpret_f32" (f32.const inf)) (i32.const 0x7f800000))
 (assert_return (invoke "i32.reinterpret_f32" (f32.const -inf)) (i32.const 0xff800000))
 (assert_return (invoke "i32.reinterpret_f32" (f32.const nan)) (i32.const 0x7fc00000))
-(assert_return (invoke "i32.reinterpret_f32" (f32.const -nan)) (i32.const 0xffc00000))
+;;(assert_return (invoke "i32.reinterpret_f32" (f32.const -nan)) (i32.const 0xffc00000))
 (assert_return (invoke "i32.reinterpret_f32" (f32.const nan:0x200000)) (i32.const 0x7fa00000))
-(assert_return (invoke "i32.reinterpret_f32" (f32.const -nan:0x200000)) (i32.const 0xffa00000))
+;;(assert_return (invoke "i32.reinterpret_f32" (f32.const -nan:0x200000)) (i32.const 0xffa00000))
 
 (assert_return (invoke "i64.reinterpret_f64" (f64.const 0.0)) (i64.const 0))
 (assert_return (invoke "i64.reinterpret_f64" (f64.const -0.0)) (i64.const 0x8000000000000000))
--- a/test/spec/float_exprs.wast
+++ b/test/spec/float_exprs.wast
@@ -1025,12 +1025,12 @@
 (assert_return (invoke "f32.no_fold_le_select_to_abs" (f32.const -nan)) (f32.const -nan))
 (assert_return (invoke "f32.no_fold_le_select_to_abs" (f32.const 0.0)) (f32.const -0.0))
 (assert_return (invoke "f32.no_fold_le_select_to_abs" (f32.const -0.0)) (f32.const 0.0))
-(assert_return (invoke "f32.no_fold_gt_select_to_abs" (f32.const nan:0x200000)) (f32.const -nan:0x200000))
-(assert_return (invoke "f32.no_fold_gt_select_to_abs" (f32.const -nan)) (f32.const nan))
+;;(assert_return (invoke "f32.no_fold_gt_select_to_abs" (f32.const nan:0x200000)) (f32.const -nan:0x200000))
+;;(assert_return (invoke "f32.no_fold_gt_select_to_abs" (f32.const -nan)) (f32.const nan))
 (assert_return (invoke "f32.no_fold_gt_select_to_abs" (f32.const 0.0)) (f32.const -0.0))
 (assert_return (invoke "f32.no_fold_gt_select_to_abs" (f32.const -0.0)) (f32.const 0.0))
-(assert_return (invoke "f32.no_fold_ge_select_to_abs" (f32.const nan:0x200000)) (f32.const -nan:0x200000))
-(assert_return (invoke "f32.no_fold_ge_select_to_abs" (f32.const -nan)) (f32.const nan))
+;;(assert_return (invoke "f32.no_fold_ge_select_to_abs" (f32.const nan:0x200000)) (f32.const -nan:0x200000))
+;;(assert_return (invoke "f32.no_fold_ge_select_to_abs" (f32.const -nan)) (f32.const nan))
 (assert_return (invoke "f32.no_fold_ge_select_to_abs" (f32.const 0.0)) (f32.const 0.0))
 (assert_return (invoke "f32.no_fold_ge_select_to_abs" (f32.const -0.0)) (f32.const -0.0))
 (assert_return (invoke "f64.no_fold_lt_select_to_abs" (f64.const nan:0x4000000000000)) (f64.const nan:0x4000000000000))
@@ -1104,12 +1104,12 @@
 (assert_return (invoke "f32.no_fold_le_if_to_abs" (f32.const -nan)) (f32.const -nan))
 (assert_return (invoke "f32.no_fold_le_if_to_abs" (f32.const 0.0)) (f32.const -0.0))
 (assert_return (invoke "f32.no_fold_le_if_to_abs" (f32.const -0.0)) (f32.const 0.0))
-(assert_return (invoke "f32.no_fold_gt_if_to_abs" (f32.const nan:0x200000)) (f32.const -nan:0x200000))
-(assert_return (invoke "f32.no_fold_gt_if_to_abs" (f32.const -nan)) (f32.const nan))
+;;(assert_return (invoke "f32.no_fold_gt_if_to_abs" (f32.const nan:0x200000)) (f32.const -nan:0x200000))
+;;(assert_return (invoke "f32.no_fold_gt_if_to_abs" (f32.const -nan)) (f32.const nan))
 (assert_return (invoke "f32.no_fold_gt_if_to_abs" (f32.const 0.0)) (f32.const -0.0))
 (assert_return (invoke "f32.no_fold_gt_if_to_abs" (f32.const -0.0)) (f32.const 0.0))
-(assert_return (invoke "f32.no_fold_ge_if_to_abs" (f32.const nan:0x200000)) (f32.const -nan:0x200000))
-(assert_return (invoke "f32.no_fold_ge_if_to_abs" (f32.const -nan)) (f32.const nan))
+;;(assert_return (invoke "f32.no_fold_ge_if_to_abs" (f32.const nan:0x200000)) (f32.const -nan:0x200000))
+;;(assert_return (invoke "f32.no_fold_ge_if_to_abs" (f32.const -nan)) (f32.const nan))
 (assert_return (invoke "f32.no_fold_ge_if_to_abs" (f32.const 0.0)) (f32.const 0.0))
 (assert_return (invoke "f32.no_fold_ge_if_to_abs" (f32.const -0.0)) (f32.const -0.0))
 (assert_return (invoke "f64.no_fold_lt_if_to_abs" (f64.const nan:0x4000000000000)) (f64.const nan:0x4000000000000))
--- a/test/spec/float_misc.wast
+++ b/test/spec/float_misc.wast
@@ -594,8 +594,8 @@
 (assert_return (invoke "f64.abs" (f64.const nan:0x0f1e27a6b)) (f64.const nan:0x0f1e27a6b))
 (assert_return (invoke "f64.abs" (f64.const -nan:0x0f1e27a6b)) (f64.const nan:0x0f1e27a6b))
 
-(assert_return (invoke "f32.neg" (f32.const nan:0x0f1e2)) (f32.const -nan:0x0f1e2))
-(assert_return (invoke "f32.neg" (f32.const -nan:0x0f1e2)) (f32.const nan:0x0f1e2))
+;;(assert_return (invoke "f32.neg" (f32.const nan:0x0f1e2)) (f32.const -nan:0x0f1e2))
+;;(assert_return (invoke "f32.neg" (f32.const -nan:0x0f1e2)) (f32.const nan:0x0f1e2))
 (assert_return (invoke "f64.neg" (f64.const nan:0x0f1e27a6b)) (f64.const -nan:0x0f1e27a6b))
 (assert_return (invoke "f64.neg" (f64.const -nan:0x0f1e27a6b)) (f64.const nan:0x0f1e27a6b))
 
--- a/test/spec/simd.wast
+++ b/test/spec/simd.wast
@@ -953,7 +953,7 @@
 
 ;; f32x4 arithmetic
 (assert_return (invoke "f32x4.abs" (v128.const f32x4 -0 nan -inf 5)) (v128.const f32x4 0 nan inf 5))
-(assert_return (invoke "f32x4.neg" (v128.const f32x4 -0 nan -inf 5)) (v128.const f32x4 0 -nan inf -5))
+;;(assert_return (invoke "f32x4.neg" (v128.const f32x4 -0 nan -inf 5)) (v128.const f32x4 0 -nan inf -5))
 (assert_return (invoke "f32x4.sqrt" (v128.const f32x4 -0 nan inf 4)) (v128.const f32x4 -0 nan inf 2))
 (assert_return (invoke "f32x4.add" (v128.const f32x4 nan -nan inf 42) (v128.const f32x4 42 inf inf 1)) (v128.const f32x4 nan nan inf 43))
 (assert_return (invoke "f32x4.sub" (v128.const f32x4 nan -nan inf 42) (v128.const f32x4 42 inf -inf 1)) (v128.const f32x4 nan nan inf 41))
--- a/test/gtest/wat-lexer.cpp
+++ b/test/gtest/wat-lexer.cpp
@@ -811,7 +811,7 @@
     ASSERT_TRUE(Lexer(nan).takeF32());
     float f = *Lexer(nan).takeF32();
     EXPECT_TRUE(std::isnan(f));
-    EXPECT_TRUE(std::signbit(f));
+    // EXPECT_TRUE(std::signbit(f));
     EXPECT_EQ(payload(f), fnanDefault);
 
     ASSERT_TRUE(Lexer(nan).takeF64());