From 19b5113c8d948f7324b4ef8826d1833e84ba8b49 Mon Sep 17 00:00:00 2001
From: "dragan.mladjenovic" <dragan.mladjenovic@rt-rk.com>
Date: Wed, 14 Mar 2018 19:24:01 +0100
Subject: [PATCH]  rustc_trans: fix small aggregate returns for big-endian
 mips64 FFI

 Current model of threating small aggregate returns as smallest encompassing integer works only for little-endian mips64.
 The patch forces small aggregate return values to be viewed as one or two i64 chunks leaving to the casting implementation
 to handle endianes differences.
---
 src/librustc_trans/cabi_mips64.rs | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/src/librustc_trans/cabi_mips64.rs b/src/librustc_trans/cabi_mips64.rs
index 94bf53cee1edb..231fe4c6edb67 100644
--- a/src/librustc_trans/cabi_mips64.rs
+++ b/src/librustc_trans/cabi_mips64.rs
@@ -28,18 +28,6 @@ fn extend_integer_width_mips(arg: &mut ArgType, bits: u64) {
     arg.extend_integer_width_to(bits);
 }
 
-fn bits_to_int_reg(bits: u64) -> Reg {
-    if bits <= 8 {
-        Reg::i8()
-    } else if bits <= 16 {
-        Reg::i16()
-    } else if bits <= 32 {
-        Reg::i32()
-    } else {
-        Reg::i64()
-    }
-}
-
 fn float_reg<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, ret: &ArgType<'tcx>, i: usize) -> Option<Reg> {
     match ret.layout.field(cx, i).abi {
         layout::Abi::Scalar(ref scalar) => match scalar.value {
@@ -82,7 +70,7 @@ fn classify_ret_ty<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>, ret: &mut ArgType<'tcx>)
 
         // Cast to a uniform int structure
         ret.cast_to(Uniform {
-            unit: bits_to_int_reg(bits),
+            unit: Reg::i64(),
             total: size
         });
     } else {