From: Connor Abbott <cwabbott0@gmail.com>
Date: Tue, 20 Aug 2019 10:31:55 +0000 (+0200)
Subject: ac/nir: Handle const array offsets in get_deref_offset()
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bb42c896fe9a1057f8e630480541938225ce0149;p=platform%2Fupstream%2Fmesa.git

ac/nir: Handle const array offsets in get_deref_offset()

Some users of this function (e.g. GS inputs) currently only work with
constant offsets. We got lucky since all the tests used an array index
of 0, so the non-constant part was always 0. But we still need to handle
this.

This doesn't fix any CTS test, but was noticed while debugging one.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
---

diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index 0b06290..e6795ba 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -1939,12 +1939,17 @@ get_deref_offset(struct ac_nir_context *ctx, nir_deref_instr *instr,
 			}
 		} else if(path.path[idx_lvl]->deref_type == nir_deref_type_array) {
 			unsigned size = glsl_count_attribute_slots(path.path[idx_lvl]->type, vs_in);
-			LLVMValueRef array_off = LLVMBuildMul(ctx->ac.builder, LLVMConstInt(ctx->ac.i32, size, 0),
-			                                      get_src(ctx, path.path[idx_lvl]->arr.index), "");
-			if (offset)
-				offset = LLVMBuildAdd(ctx->ac.builder, offset, array_off, "");
-			else
-				offset = array_off;
+			if (nir_src_is_const(path.path[idx_lvl]->arr.index)) {
+				const_offset += size *
+					nir_src_as_uint(path.path[idx_lvl]->arr.index);
+			} else {
+				LLVMValueRef array_off = LLVMBuildMul(ctx->ac.builder, LLVMConstInt(ctx->ac.i32, size, 0),
+								      get_src(ctx, path.path[idx_lvl]->arr.index), "");
+				if (offset)
+					offset = LLVMBuildAdd(ctx->ac.builder, offset, array_off, "");
+				else
+					offset = array_off;
+			}
 		} else
 			unreachable("Uhandled deref type in get_deref_instr_offset");
 	}