gallivm: fix half to float conversions with llvm 11

From Roland Scheidegger
51a82ec3e437d1d2dc4c688578640d25b3e7f0a2 in mainline Mesa

1 files changed, 24 insertions, 10 deletions

diff --git a/lib/mesa/src/gallium/auxiliary/gallivm/lp_bld_conv.c b/lib/mesa/src/gallium/auxiliary/gallivm/lp_bld_conv.c
index c688965a7..556babdd2 100644
--- a/lib/mesa/src/gallium/auxiliary/gallivm/lp_bld_conv.c
+++ b/lib/mesa/src/gallium/auxiliary/gallivm/lp_bld_conv.c
@@ -103,19 +103,33 @@ lp_build_half_to_float(struct gallivm_state *gallivm,
 
    if (util_cpu_caps.has_f16c &&
        (src_length == 4 || src_length == 8)) {
-      const char *intrinsic = NULL;
-      if (src_length == 4) {
-         src = lp_build_pad_vector(gallivm, src, 8);
-         intrinsic = "llvm.x86.vcvtph2ps.128";
-      }
-      else {
-         intrinsic = "llvm.x86.vcvtph2ps.256";
+      if (LLVM_VERSION_MAJOR < 11) {
+         const char *intrinsic = NULL;
+         if (src_length == 4) {
+            src = lp_build_pad_vector(gallivm, src, 8);
+            intrinsic = "llvm.x86.vcvtph2ps.128";
+         }
+         else {
+            intrinsic = "llvm.x86.vcvtph2ps.256";
+         }
+         return lp_build_intrinsic_unary(builder, intrinsic,
+                                         lp_build_vec_type(gallivm, f32_type), src);
+      } else {
+         /*
+          * XXX: could probably use on other archs as well.
+          * But if the cpu doesn't support it natively it looks like the backends still
+          * can't lower it and will try to call out to external libraries, which will crash.
+          */
+         /*
+          * XXX: lp_build_vec_type() would use int16 vector. Probably need to revisit
+          * this at some point.
+          */
+         src = LLVMBuildBitCast(builder, src,
+                                LLVMVectorType(LLVMHalfTypeInContext(gallivm->context), src_length), "");
+         return LLVMBuildFPExt(builder, src, lp_build_vec_type(gallivm, f32_type), "");
       }
-      return lp_build_intrinsic_unary(builder, intrinsic,
-                                      lp_build_vec_type(gallivm, f32_type), src);
    }
 
-   /* Convert int16 vector to int32 vector by zero ext (might generate bad code) */
    h = LLVMBuildZExt(builder, src, int_vec_type, "");
    return lp_build_smallfloat_to_float(gallivm, f32_type, h, 10, 5, 0, true);
 }