gallivm: add cttz wrapper

this will be used to write find_lsb support

Reviewed-by: Roland Scheidegger <sroland@vmware.com>

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_bitarit.c b/src/gallium/auxiliary/gallivm/lp_bld_bitarit.c
index 998d359..c717b98 100644 (file)
--- a/src/gallium/auxiliary/gallivm/lp_bld_bitarit.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_bitarit.c
@@ -252,3 +252,17 @@ lp_build_popcount(struct lp_build_context *bld, LLVMValueRef a)
    result = lp_build_intrinsic_unary(builder, intr_str, bld->vec_type, a);
    return result;
 }
+
+LLVMValueRef
+lp_build_cttz(struct lp_build_context *bld, LLVMValueRef a)
+{
+   LLVMBuilderRef builder = bld->gallivm->builder;
+   LLVMValueRef result;
+   char intr_str[256];
+
+   lp_format_intrinsic(intr_str, sizeof(intr_str), "llvm.cttz", bld->vec_type);
+
+   LLVMValueRef undef_val = LLVMConstNull(LLVMInt1TypeInContext(bld->gallivm->context));
+   result = lp_build_intrinsic_binary(builder, intr_str, bld->vec_type, a, undef_val);
+   return result;
+}

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_bitarit.h b/src/gallium/auxiliary/gallivm/lp_bld_bitarit.h
index e0f4f4a..989ce5c 100644 (file)
--- a/src/gallium/auxiliary/gallivm/lp_bld_bitarit.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_bitarit.h
@@ -73,4 +73,7 @@ lp_build_not(struct lp_build_context *bld, LLVMValueRef a);
 
 LLVMValueRef
 lp_build_popcount(struct lp_build_context *bld, LLVMValueRef a);
+
+LLVMValueRef
+lp_build_cttz(struct lp_build_context *bld, LLVMValueRef a);
 #endif /* !LP_BLD_ARIT_H */