[PPC64LE] Implement little-endian semantics for vec_unpack[hl]

The PowerPC vector-unpack-high and vector-unpack-low instructions
are defined architecturally with a big-endian bias, in that the vector
element numbering is assumed to be "left to right" regardless of
whether the processor is in big-endian or little-endian mode.  This
effectively reverses the meaning of "high" and "low."  Such a
definition is unnatural for little-endian code generation.

To facilitate ease of porting, the vec_unpackh and vec_unpackl
interfaces are designed to use natural element ordering, so that
elements are numbered according to little-endian design principles
when code is generated for a little-endian target.  The desired
semantics can be achieved by using the opposite instruction for
little-endian mode.  That is, when a call to vec_unpackh appears in
the code, a vector-unpack-low is generated, and when a call to
vec_unpackl appears in the code, a vector-unpack-high is generated.

The correctness of this code is tested by the new unpack.c test
added in a previous patch, as well as the modifications to
builtins-ppc-altivec.c in the present patch.

Note that these interfaces were originally incorrectly implemented
when they take a vector pixel argument.  This patch corrects this
implementation for both big- and little-endian code generation.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@210391 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Headers/altivec.h b/lib/Headers/altivec.h
index 7dfb74e0698c847fb78252ab118c562a23116338..65990e0db404314fc22b4c60fa2e0a12c70c8106 100644 (file)
--- a/lib/Headers/altivec.h
+++ b/lib/Headers/altivec.h
@@ -8430,34 +8430,57 @@ vec_vrfiz(vector float __a)
 
 /* vec_unpackh */
 
+/* The vector unpack instructions all have a big-endian bias, so for
+   little endian we must reverse the meanings of "high" and "low."  */
+
 static vector short __ATTRS_o_ai
 vec_unpackh(vector signed char __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return __builtin_altivec_vupklsb((vector char)__a);
+#else
   return __builtin_altivec_vupkhsb((vector char)__a);
+#endif
 }
 
 static vector bool short __ATTRS_o_ai
 vec_unpackh(vector bool char __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return (vector bool short)__builtin_altivec_vupklsb((vector char)__a);
+#else
   return (vector bool short)__builtin_altivec_vupkhsb((vector char)__a);
+#endif
 }
 
 static vector int __ATTRS_o_ai
 vec_unpackh(vector short __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return __builtin_altivec_vupklsh(__a);
+#else
   return __builtin_altivec_vupkhsh(__a);
+#endif
 }
 
 static vector bool int __ATTRS_o_ai
 vec_unpackh(vector bool short __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return (vector bool int)__builtin_altivec_vupklsh((vector short)__a);
+#else
   return (vector bool int)__builtin_altivec_vupkhsh((vector short)__a);
+#endif
 }
 
 static vector unsigned int __ATTRS_o_ai
 vec_unpackh(vector pixel __a)
 {
-  return (vector unsigned int)__builtin_altivec_vupkhsh((vector short)__a);
+#ifdef __LITTLE_ENDIAN__
+  return (vector unsigned int)__builtin_altivec_vupklpx((vector short)__a);
+#else
+  return (vector unsigned int)__builtin_altivec_vupkhpx((vector short)__a);
+#endif
 }
 
 /* vec_vupkhsb */
@@ -8465,13 +8488,21 @@ vec_unpackh(vector pixel __a)
 static vector short __ATTRS_o_ai
 vec_vupkhsb(vector signed char __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return __builtin_altivec_vupklsb((vector char)__a);
+#else
   return __builtin_altivec_vupkhsb((vector char)__a);
+#endif
 }
 
 static vector bool short __ATTRS_o_ai
 vec_vupkhsb(vector bool char __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return (vector bool short)__builtin_altivec_vupklsb((vector char)__a);
+#else
   return (vector bool short)__builtin_altivec_vupkhsb((vector char)__a);
+#endif
 }
 
 /* vec_vupkhsh */
@@ -8479,19 +8510,31 @@ vec_vupkhsb(vector bool char __a)
 static vector int __ATTRS_o_ai
 vec_vupkhsh(vector short __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return __builtin_altivec_vupklsh(__a);
+#else
   return __builtin_altivec_vupkhsh(__a);
+#endif
 }
 
 static vector bool int __ATTRS_o_ai
 vec_vupkhsh(vector bool short __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return (vector bool int)__builtin_altivec_vupklsh((vector short)__a);
+#else
   return (vector bool int)__builtin_altivec_vupkhsh((vector short)__a);
+#endif
 }
 
 static vector unsigned int __ATTRS_o_ai
 vec_vupkhsh(vector pixel __a)
 {
-  return (vector unsigned int)__builtin_altivec_vupkhsh((vector short)__a);
+#ifdef __LITTLE_ENDIAN__
+  return (vector unsigned int)__builtin_altivec_vupklpx((vector short)__a);
+#else
+  return (vector unsigned int)__builtin_altivec_vupkhpx((vector short)__a);
+#endif
 }
 
 /* vec_unpackl */
@@ -8499,31 +8542,51 @@ vec_vupkhsh(vector pixel __a)
 static vector short __ATTRS_o_ai
 vec_unpackl(vector signed char __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return __builtin_altivec_vupkhsb((vector char)__a);
+#else
   return __builtin_altivec_vupklsb((vector char)__a);
+#endif
 }
 
 static vector bool short __ATTRS_o_ai
 vec_unpackl(vector bool char __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return (vector bool short)__builtin_altivec_vupkhsb((vector char)__a);
+#else
   return (vector bool short)__builtin_altivec_vupklsb((vector char)__a);
+#endif
 }
 
 static vector int __ATTRS_o_ai
 vec_unpackl(vector short __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return __builtin_altivec_vupkhsh(__a);
+#else
   return __builtin_altivec_vupklsh(__a);
+#endif
 }
 
 static vector bool int __ATTRS_o_ai
 vec_unpackl(vector bool short __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return (vector bool int)__builtin_altivec_vupkhsh((vector short)__a);
+#else
   return (vector bool int)__builtin_altivec_vupklsh((vector short)__a);
+#endif
 }
 
 static vector unsigned int __ATTRS_o_ai
 vec_unpackl(vector pixel __a)
 {
-  return (vector unsigned int)__builtin_altivec_vupklsh((vector short)__a);
+#ifdef __LITTLE_ENDIAN__
+  return (vector unsigned int)__builtin_altivec_vupkhpx((vector short)__a);
+#else
+  return (vector unsigned int)__builtin_altivec_vupklpx((vector short)__a);
+#endif
 }
 
 /* vec_vupklsb */
@@ -8531,13 +8594,21 @@ vec_unpackl(vector pixel __a)
 static vector short __ATTRS_o_ai
 vec_vupklsb(vector signed char __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return __builtin_altivec_vupkhsb((vector char)__a);
+#else
   return __builtin_altivec_vupklsb((vector char)__a);
+#endif
 }
 
 static vector bool short __ATTRS_o_ai
 vec_vupklsb(vector bool char __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return (vector bool short)__builtin_altivec_vupkhsb((vector char)__a);
+#else
   return (vector bool short)__builtin_altivec_vupklsb((vector char)__a);
+#endif
 }
 
 /* vec_vupklsh */
@@ -8545,19 +8616,31 @@ vec_vupklsb(vector bool char __a)
 static vector int __ATTRS_o_ai
 vec_vupklsh(vector short __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return __builtin_altivec_vupkhsh(__a);
+#else
   return __builtin_altivec_vupklsh(__a);
+#endif
 }
 
 static vector bool int __ATTRS_o_ai
 vec_vupklsh(vector bool short __a)
 {
+#ifdef __LITTLE_ENDIAN__
+  return (vector bool int)__builtin_altivec_vupkhsh((vector short)__a);
+#else
   return (vector bool int)__builtin_altivec_vupklsh((vector short)__a);
+#endif
 }
 
 static vector unsigned int __ATTRS_o_ai
 vec_vupklsh(vector pixel __a)
 {
-  return (vector unsigned int)__builtin_altivec_vupklsh((vector short)__a);
+#ifdef __LITTLE_ENDIAN__
+  return (vector unsigned int)__builtin_altivec_vupkhpx((vector short)__a);
+#else
+  return (vector unsigned int)__builtin_altivec_vupklpx((vector short)__a);
+#endif
 }
 
 /* vec_xor */

diff --git a/test/CodeGen/builtins-ppc-altivec.c b/test/CodeGen/builtins-ppc-altivec.c
index 8a846bdec8d6f39d9037d53465e5f0e680a6207b..8277f5dda7dd01e089e5d34d7ef3ec9c38aa5904 100644 (file)
--- a/test/CodeGen/builtins-ppc-altivec.c
+++ b/test/CodeGen/builtins-ppc-altivec.c
@@ -5173,84 +5173,84 @@ void test6() {
   /* vec_unpackh */
   res_vs  = vec_unpackh(vsc);
 // CHECK: @llvm.ppc.altivec.vupkhsb
-// CHECK-LE: @llvm.ppc.altivec.vupkhsb
+// CHECK-LE: @llvm.ppc.altivec.vupklsb
 
   res_vbs = vec_unpackh(vbc);
 // CHECK: @llvm.ppc.altivec.vupkhsb
-// CHECK-LE: @llvm.ppc.altivec.vupkhsb
+// CHECK-LE: @llvm.ppc.altivec.vupklsb
 
   res_vi  = vec_unpackh(vs);
 // CHECK: @llvm.ppc.altivec.vupkhsh
-// CHECK-LE: @llvm.ppc.altivec.vupkhsh
+// CHECK-LE: @llvm.ppc.altivec.vupklsh
 
   res_vbi = vec_unpackh(vbs);
 // CHECK: @llvm.ppc.altivec.vupkhsh
-// CHECK-LE: @llvm.ppc.altivec.vupkhsh
+// CHECK-LE: @llvm.ppc.altivec.vupklsh
 
   res_vui = vec_unpackh(vp);
-// CHECK: @llvm.ppc.altivec.vupkhsh
-// CHECK-LE: @llvm.ppc.altivec.vupkhsh
+// CHECK: @llvm.ppc.altivec.vupkhpx
+// CHECK-LE: @llvm.ppc.altivec.vupklpx
 
   res_vs  = vec_vupkhsb(vsc);
 // CHECK: @llvm.ppc.altivec.vupkhsb
-// CHECK-LE: @llvm.ppc.altivec.vupkhsb
+// CHECK-LE: @llvm.ppc.altivec.vupklsb
 
   res_vbs = vec_vupkhsb(vbc);
 // CHECK: @llvm.ppc.altivec.vupkhsb
-// CHECK-LE: @llvm.ppc.altivec.vupkhsb
+// CHECK-LE: @llvm.ppc.altivec.vupklsb
 
   res_vi  = vec_vupkhsh(vs);
 // CHECK: @llvm.ppc.altivec.vupkhsh
-// CHECK-LE: @llvm.ppc.altivec.vupkhsh
+// CHECK-LE: @llvm.ppc.altivec.vupklsh
 
   res_vbi = vec_vupkhsh(vbs);
 // CHECK: @llvm.ppc.altivec.vupkhsh
-// CHECK-LE: @llvm.ppc.altivec.vupkhsh
+// CHECK-LE: @llvm.ppc.altivec.vupklsh
 
   res_vui = vec_vupkhsh(vp);
-// CHECK: @llvm.ppc.altivec.vupkhsh
-// CHECK-LE: @llvm.ppc.altivec.vupkhsh
+// CHECK: @llvm.ppc.altivec.vupkhpx
+// CHECK-LE: @llvm.ppc.altivec.vupklpx
 
   /* vec_unpackl */
   res_vs  = vec_unpackl(vsc);
 // CHECK: @llvm.ppc.altivec.vupklsb
-// CHECK-LE: @llvm.ppc.altivec.vupklsb
+// CHECK-LE: @llvm.ppc.altivec.vupkhsb
 
   res_vbs = vec_unpackl(vbc);
 // CHECK: @llvm.ppc.altivec.vupklsb
-// CHECK-LE: @llvm.ppc.altivec.vupklsb
+// CHECK-LE: @llvm.ppc.altivec.vupkhsb
 
   res_vi  = vec_unpackl(vs);
 // CHECK: @llvm.ppc.altivec.vupklsh
-// CHECK-LE: @llvm.ppc.altivec.vupklsh
+// CHECK-LE: @llvm.ppc.altivec.vupkhsh
 
   res_vbi = vec_unpackl(vbs);
 // CHECK: @llvm.ppc.altivec.vupklsh
-// CHECK-LE: @llvm.ppc.altivec.vupklsh
+// CHECK-LE: @llvm.ppc.altivec.vupkhsh
 
   res_vui = vec_unpackl(vp);
-// CHECK: @llvm.ppc.altivec.vupklsh
-// CHECK-LE: @llvm.ppc.altivec.vupklsh
+// CHECK: @llvm.ppc.altivec.vupklpx
+// CHECK-LE: @llvm.ppc.altivec.vupkhpx
 
   res_vs  = vec_vupklsb(vsc);
 // CHECK: @llvm.ppc.altivec.vupklsb
-// CHECK-LE: @llvm.ppc.altivec.vupklsb
+// CHECK-LE: @llvm.ppc.altivec.vupkhsb
 
   res_vbs = vec_vupklsb(vbc);
 // CHECK: @llvm.ppc.altivec.vupklsb
-// CHECK-LE: @llvm.ppc.altivec.vupklsb
+// CHECK-LE: @llvm.ppc.altivec.vupkhsb
 
   res_vi  = vec_vupklsh(vs);
 // CHECK: @llvm.ppc.altivec.vupklsh
-// CHECK-LE: @llvm.ppc.altivec.vupklsh
+// CHECK-LE: @llvm.ppc.altivec.vupkhsh
 
   res_vbi = vec_vupklsh(vbs);
 // CHECK: @llvm.ppc.altivec.vupklsh
-// CHECK-LE: @llvm.ppc.altivec.vupklsh
+// CHECK-LE: @llvm.ppc.altivec.vupkhsh
 
   res_vui = vec_vupklsh(vp);
-// CHECK: @llvm.ppc.altivec.vupklsh
-// CHECK-LE: @llvm.ppc.altivec.vupklsh
+// CHECK: @llvm.ppc.altivec.vupklpx
+// CHECK-LE: @llvm.ppc.altivec.vupkhpx
 
   /* vec_xor */
   res_vsc = vec_xor(vsc, vsc);