From: Nicolai Hähnle <nicolai.haehnle@amd.com>
Date: Wed, 9 Nov 2016 11:44:47 +0000 (+0100)
Subject: gallivm: fix [IU]MUL_HI regression harder
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=b46a9c570f431d3953a3ba31ffe76ad17568e522;p=mesa.git

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@vmware.com>
---

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
index 43ad238393c..5553cb10dc2 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;
 }