Add the intrinsic __builtin_convertvector

LLVM supports applying conversion instructions to vectors of the same number of
elements (fptrunc, fptosi, etc.) but there had been no way for a Clang user to
cause such instructions to be generated when using builtin vector types.

C-style casting on vectors is already defined in terms of bitcasts, and so
cannot be used for these conversions as well (without leading to a very
confusing set of semantics). As a result, this adds a __builtin_convertvector
intrinsic (patterned after the OpenCL __builtin_astype intrinsic). This is
intended to aid the creation of vector intrinsic headers that create generic IR
instead of target-dependent intrinsics (in other words, this is a generic
_mm_cvtepi32_ps). As noted in the documentation, the action of
__builtin_convertvector is defined in terms of the action of a C-style cast on
each vector element.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190915 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 0 deletions

diff --git a/test/PCH/exprs.h b/test/PCH/exprs.h
index d08b1f64ed..d6735a727a 100644
--- a/test/PCH/exprs.h
+++ b/test/PCH/exprs.h
@@ -102,6 +102,10 @@ typedef typeof(__builtin_choose_expr(17 > 19, d0, 1)) choose_expr;
 // ShuffleVectorExpr
 typedef typeof(__builtin_shufflevector(vec2, vec2b, 2, 1)) shuffle_expr;
 
+// ConvertVectorExpr
+typedef __attribute__(( ext_vector_type(2) )) float float2;
+typedef typeof(__builtin_convertvector(vec2, float2)) convert_expr;
+
 // GenericSelectionExpr
 typedef typeof(_Generic(i, char*: 0, int: 0., default: hello))
   generic_selection_expr;