Mesa (master): gallivm: fix [IU]MUL_HI regression harder

[Nicolai Hähnle]

Module: Mesa
Branch: master
Commit: b46a9c570f431d3953a3ba31ffe76ad17568e522
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=b46a9c570f431d3953a3ba31ffe76ad17568e522

Author: Nicolai Hähnle <nicolai.haehnle at amd.com>
Date:   Wed Nov  9 12:44:47 2016 +0100

gallivm: fix [IU]MUL_HI regression harder

The fix in commit 88f791db75e9f065bac8134e0937e1b76600aa36 was insufficient
for radeonsi because the vector case was not handled properly. It seems
piglit only covers the scalar case, unfortunately.

Fixes GL45-CTS.shader_bitfield_operation.[iu]mulExtended.*

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

---

 src/gallium/auxiliary/gallivm/lp_bld_arit.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
index 43ad238..5553cb1 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
@@ -1237,16 +1237,15 @@ lp_build_mul_32_lohi(struct lp_build_context *bld,
 {
    struct gallivm_state *gallivm = bld->gallivm;
    LLVMBuilderRef builder = gallivm->builder;
-   LLVMValueRef tmp;
+   LLVMValueRef tmp, shift, res_lo;
    struct lp_type type_tmp;
-   LLVMTypeRef wide_type, cast_type;
+   LLVMTypeRef wide_type, narrow_type;
 
    type_tmp = bld->type;
+   narrow_type = lp_build_vec_type(gallivm, type_tmp);
    type_tmp.width *= 2;
    wide_type = lp_build_vec_type(gallivm, type_tmp);
-   type_tmp = bld->type;
-   type_tmp.length *= 2;
-   cast_type = lp_build_vec_type(gallivm, type_tmp);
+   shift = lp_build_const_vec(gallivm, type_tmp, 32);
 
    if (bld->type.sign) {
       a = LLVMBuildSExt(builder, a, wide_type, "");
@@ -1256,9 +1255,14 @@ lp_build_mul_32_lohi(struct lp_build_context *bld,
       b = LLVMBuildZExt(builder, b, wide_type, "");
    }
    tmp = LLVMBuildMul(builder, a, b, "");
-   tmp = LLVMBuildBitCast(builder, tmp, cast_type, "");
-   *res_hi = lp_build_uninterleave1(gallivm, bld->type.length * 2, tmp, 1);
-   return lp_build_uninterleave1(gallivm, bld->type.length * 2, tmp, 0);
+
+   res_lo = LLVMBuildTrunc(builder, tmp, narrow_type, "");
+
+   /* Since we truncate anyway, LShr and AShr are equivalent. */
+   tmp = LLVMBuildLShr(builder, tmp, shift, "");
+   *res_hi = LLVMBuildTrunc(builder, tmp, narrow_type, "");
+
+   return res_lo;
 }