From 933e701dac1936c6f15c765b5687fbc623464ec7 Mon Sep 17 00:00:00 2001
From: Mike Sperber <sperber@deinprogramm.de>
Date: Thu, 22 Mar 2012 18:00:31 +0100
Subject: Unbreak floating point on middle-endian machines.

On some ARMs (and maybe other platforms), doubles are stored with the
the two 32-bit words reversed with respect to more common
architectures.

The symptom is this:

> io_lib:write(1.0).
"0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000005299808824"

Detect that and account for it when decoding floats.
---
 erts/emulator/beam/erl_bits.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

(limited to 'erts/emulator/beam')

diff --git a/erts/emulator/beam/erl_bits.c b/erts/emulator/beam/erl_bits.c
index 6f7309f493..b7c82935ff 100644
--- a/erts/emulator/beam/erl_bits.c
+++ b/erts/emulator/beam/erl_bits.c
@@ -1005,8 +1005,13 @@ erts_new_bs_put_float(Process *c_p, Eterm arg, Uint num_bits, int flags)
 
 	    if (is_float(arg)) {
 		FloatDef *fdp = (FloatDef*)(float_val(arg) + 1);
+#ifdef DOUBLE_MIDDLE_ENDIAN
+		a = fdp->fw[1];
+		b = fdp->fw[0];
+#else
 		a = fdp->fw[0];
 		b = fdp->fw[1];
+#endif
 	    } else if (is_small(arg)) {
 		u.f64 = (double) signed_val(arg);
 		a = u.i32[0];
@@ -1015,8 +1020,13 @@ erts_new_bs_put_float(Process *c_p, Eterm arg, Uint num_bits, int flags)
 		if (big_to_double(arg, &u.f64) < 0) {
 		    return 0;
 		}
+#ifdef DOUBLE_MIDDLE_ENDIAN
+		a = u.i32[1];
+		b = u.i32[0];
+#else
 		a = u.i32[0];
 		b = u.i32[1];
+#endif
 	    } else {
 		return 0;
 	    }
-- 
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