From 5492101fc0a6941cb94692efdef35ffb6f2ebf3e Mon Sep 17 00:00:00 2001
From: Jeffrey Walton <noloader@gmail.com>
Date: Wed, 21 Nov 2018 17:37:19 -0500
Subject: [PATCH] Fix XLC 13.1 debug builds on Linux

---
 ppc_simd.h | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/ppc_simd.h b/ppc_simd.h
index ed1dffed..1707c4d4 100644
--- a/ppc_simd.h
+++ b/ppc_simd.h
@@ -829,9 +829,11 @@ inline T VecShiftLeftOctet(const T vec)
     else
     {
 #if (CRYPTOPP_BIG_ENDIAN)
-    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)zero, C);
+    enum { R=C&0xf };
+    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)zero, R);
 #else
-    return (T)vec_sld((uint8x16_p)zero, (uint8x16_p)vec, 16-C);
+    enum { R=(16-C)&0xf };  // Linux xlC 13.1 workaround in Debug builds
+    return (T)vec_sld((uint8x16_p)zero, (uint8x16_p)vec, R);
 #endif
     }
 }
@@ -872,9 +874,11 @@ inline T VecShiftRightOctet(const T vec)
     else
     {
 #if (CRYPTOPP_BIG_ENDIAN)
-    return (T)vec_sld((uint8x16_p)zero, (uint8x16_p)vec, 16-C);
+    enum { R=(16-C)&0xf };  // Linux xlC 13.1 workaround in Debug builds
+    return (T)vec_sld((uint8x16_p)zero, (uint8x16_p)vec, R);
 #else
-    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)zero, C);
+    enum { R=C&0xf };
+    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)zero, R);
 #endif
     }
 }
@@ -893,11 +897,12 @@ inline T VecShiftRightOctet(const T vec)
 template <unsigned int C, class T>
 inline T VecRotateLeftOctet(const T vec)
 {
-    enum { R = C&0xf };
 #if (CRYPTOPP_BIG_ENDIAN)
+    enum { R = C&0xf };
     return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, R);
 #else
-    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, 16-R);
+    enum { R=(16-C)&0xf };  // Linux xlC 13.1 workaround in Debug builds
+    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, R);
 #endif
 }
 
@@ -915,10 +920,11 @@ inline T VecRotateLeftOctet(const T vec)
 template <unsigned int C, class T>
 inline T VecRotateRightOctet(const T vec)
 {
-    enum { R = C&0xf };
 #if (CRYPTOPP_BIG_ENDIAN)
-    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, 16-R);
+    enum { R=(16-C)&0xf };  // Linux xlC 13.1 workaround in Debug builds
+    return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, R);
 #else
+    enum { R = C&0xf };
     return (T)vec_sld((uint8x16_p)vec, (uint8x16_p)vec, R);
 #endif
 }