diff --git a/src/gallium/auxiliary/gallivm/lp_bld_format_s3tc.c b/src/gallium/auxiliary/gallivm/lp_bld_format_s3tc.c
index e17c7881e7d..497d403fad3 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_format_s3tc.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_format_s3tc.c
@@ -2365,6 +2365,9 @@ lp_build_gather_rgtc(struct gallivm_state *gallivm,
                                              lp_build_const_int32(gallivm, 2), "");
          *green_hi = LLVMBuildExtractElement(builder, elem,
                                              lp_build_const_int32(gallivm, 3), "");
+      } else {
+         *green_lo = NULL;
+         *green_hi = NULL;
       }
    } else {
       LLVMValueRef tmp[4];
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_nir.c b/src/gallium/auxiliary/gallivm/lp_bld_nir.c
index 51c6ecbd615..5d2c27ec29a 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_nir.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_nir.c
@@ -1053,6 +1053,7 @@ static void visit_load_const(struct lp_build_nir_context *bld_base,
    struct lp_build_context *int_bld = get_int_bld(bld_base, true, instr->def.bit_size);
    for (unsigned i = 0; i < instr->def.num_components; i++)
       result[i] = lp_build_const_int_vec(bld_base->base.gallivm, int_bld->type, instr->def.bit_size == 32 ? instr->value[i].u32 : instr->value[i].u64);
+   memset(&result[instr->def.num_components], 0, NIR_MAX_VEC_COMPONENTS - instr->def.num_components);
    assign_ssa_dest(bld_base, &instr->def, result);
 }
 
@@ -2120,6 +2121,7 @@ static void visit_ssa_undef(struct lp_build_nir_context *bld_base,
    struct lp_build_context *undef_bld = get_int_bld(bld_base, true, instr->def.bit_size);
    for (unsigned i = 0; i < num_components; i++)
       undef[i] = LLVMGetUndef(undef_bld->vec_type);
+   memset(&undef[num_components], 0, NIR_MAX_VEC_COMPONENTS - num_components);
    assign_ssa_dest(bld_base, &instr->def, undef);
 }