intel/compiler: Generalize shader relocations a bit

This commit adds a delta to be added to the relocated value as well as
the possibility of multiple types of relocations.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8637>

src/intel/compiler/brw_compiler.c

@@ -284,10 +284,17 @@ brw_write_shader_relocs(const struct intel_device_info *devinfo,
 {
    for (unsigned i = 0; i < prog_data->num_relocs; i++) {
       assert(prog_data->relocs[i].offset % 8 == 0);
-      brw_inst *inst = (brw_inst *)(program + prog_data->relocs[i].offset);
+      void *dst = program + prog_data->relocs[i].offset;
       for (unsigned j = 0; j < num_values; j++) {
          if (prog_data->relocs[i].id == values[j].id) {
-            brw_update_reloc_imm(devinfo, inst, values[j].value);
+            uint32_t value = values[j].value + prog_data->relocs[i].delta;
+            switch (prog_data->relocs[i].type) {
+            case BRW_SHADER_RELOC_TYPE_MOV_IMM:
+               brw_update_reloc_imm(devinfo, dst, value);
+               break;
+            default:
+               unreachable("Invalid relocation type");
+            }
             break;
          }
       }

src/intel/compiler/brw_compiler.h

@@ -680,6 +680,11 @@ enum brw_shader_reloc_id {
    BRW_SHADER_RELOC_CONST_DATA_ADDR_HIGH,
 };
 
+enum brw_shader_reloc_type {
+   /** A MOV instruction with an immediate source */
+   BRW_SHADER_RELOC_TYPE_MOV_IMM,
+};
+
 /** Represents a code relocation
  *
  * Relocatable constants are immediates in the code which we want to be able
@@ -689,12 +694,18 @@ struct brw_shader_reloc {
    /** The 32-bit ID of the relocatable constant */
    uint32_t id;
 
-   /** The offset in the shader to the relocatable instruction
+   /** Type of this relocation */
+   enum brw_shader_reloc_type type;
+
+   /** The offset in the shader to the relocated value
     *
-    * This is the offset to the instruction rather than the immediate value
+    * For MOV_IMM relocs, this is an offset to the MOV instruction.  This
-    * itself.  This allows us to do some sanity checking while we relocate.
+    * allows us to do some sanity checking while we update the value.
     */
    uint32_t offset;
+
+   /** Value to be added to the relocated value before it is written */
+   uint32_t delta;
 };
 
 /** A value to write to a relocation */

src/intel/compiler/brw_eu.h

@@ -200,6 +200,9 @@ void brw_realign(struct brw_codegen *p, unsigned align);
 int brw_append_data(struct brw_codegen *p, void *data,
                     unsigned size, unsigned align);
 brw_inst *brw_next_insn(struct brw_codegen *p, unsigned opcode);
+void brw_add_reloc(struct brw_codegen *p, uint32_t id,
+                   enum brw_shader_reloc_type type,
+                   uint32_t offset, uint32_t delta);
 void brw_set_dest(struct brw_codegen *p, brw_inst *insn, struct brw_reg dest);
 void brw_set_src0(struct brw_codegen *p, brw_inst *insn, struct brw_reg reg);
 

src/intel/compiler/brw_eu_emit.c

@@ -706,6 +706,25 @@ brw_next_insn(struct brw_codegen *p, unsigned opcode)
    return insn;
 }
 
+void
+brw_add_reloc(struct brw_codegen *p, uint32_t id,
+              enum brw_shader_reloc_type type,
+              uint32_t offset, uint32_t delta)
+{
+   if (p->num_relocs + 1 > p->reloc_array_size) {
+      p->reloc_array_size = MAX2(16, p->reloc_array_size * 2);
+      p->relocs = reralloc(p->mem_ctx, p->relocs,
+                           struct brw_shader_reloc, p->reloc_array_size);
+   }
+
+   p->relocs[p->num_relocs++] = (struct brw_shader_reloc) {
+      .id = id,
+      .type = type,
+      .offset = offset,
+      .delta = delta,
+   };
+}
+
 static brw_inst *
 brw_alu1(struct brw_codegen *p, unsigned opcode,
          struct brw_reg dest, struct brw_reg src)
@@ -3690,16 +3709,8 @@ brw_MOV_reloc_imm(struct brw_codegen *p,
    assert(type_sz(src_type) == 4);
    assert(type_sz(dst.type) == 4);
 
-   if (p->num_relocs + 1 > p->reloc_array_size) {
+   brw_add_reloc(p, id, BRW_SHADER_RELOC_TYPE_MOV_IMM,
-      p->reloc_array_size = MAX2(16, p->reloc_array_size * 2);
+                 p->next_insn_offset, 0);
-      p->relocs = reralloc(p->mem_ctx, p->relocs,
-                           struct brw_shader_reloc, p->reloc_array_size);
-   }
-
-   p->relocs[p->num_relocs++] = (struct brw_shader_reloc) {
-      .id = id,
-      .offset = p->next_insn_offset,
-   };
 
    brw_MOV(p, dst, retype(brw_imm_ud(DEFAULT_PATCH_IMM), src_type));
 }