mesa: glsl: count number of temp regs used

2 files changed, 34 insertions, 3 deletions

diff --git a/src/mesa/shader/slang/slang_codegen.c b/src/mesa/shader/slang/slang_codegen.c
index f891068322c..142e240802e 100644
--- a/src/mesa/shader/slang/slang_codegen.c
+++ b/src/mesa/shader/slang/slang_codegen.c
@@ -2473,8 +2473,6 @@ _slang_gen_var_decl(slang_assemble_ctx *A, slang_variable *var)
           */
          n->Store->Swizzle = SWIZZLE_NOOP;
       }
-
-      A->program->NumTemporaries++; /* an approximation */
    }
    return n;
 }
diff --git a/src/mesa/shader/slang/slang_link.c b/src/mesa/shader/slang/slang_link.c
index 1de561930a4..53de4232bea 100644
--- a/src/mesa/shader/slang/slang_link.c
+++ b/src/mesa/shader/slang/slang_link.c
@@ -277,6 +277,36 @@ _slang_resolve_attributes(struct gl_shader_program *shProg,
 
 
 /**
+ * Scan program instructions to update the program's NumTemporaries field.
+ * Note: this implemenation relies on the code generator allocating
+ * temps in increasing order (0, 1, 2, ... ).
+ */
+static void
+_slang_count_temporaries(struct gl_program *prog)
+{
+   GLuint i, j;
+   GLint maxIndex = -1;
+
+   for (i = 0; i < prog->NumInstructions; i++) {
+      const struct prog_instruction *inst = prog->Instructions + i;
+      const GLuint numSrc = _mesa_num_inst_src_regs(inst->Opcode);
+      for (j = 0; j < numSrc; j++) {
+         if (inst->SrcReg[j].File == PROGRAM_TEMPORARY) {
+            if (maxIndex < inst->SrcReg[j].Index)
+               maxIndex = inst->SrcReg[j].Index;
+         }
+         if (inst->DstReg.File == PROGRAM_TEMPORARY) {
+            if (maxIndex < inst->DstReg.Index)
+               maxIndex = inst->DstReg.Index;
+         }
+      }
+   }
+
+   prog->NumTemporaries = (GLuint) (maxIndex + 1);
+}
+
+
+/**
  * Scan program instructions to update the program's InputsRead and
  * OutputsWritten fields.
  */
@@ -459,6 +489,7 @@ _slang_link(GLcontext *ctx,
 
    if (shProg->VertexProgram) {
       _slang_update_inputs_outputs(&shProg->VertexProgram->Base);
+      _slang_count_temporaries(&shProg->VertexProgram->Base);
       if (!(shProg->VertexProgram->Base.OutputsWritten & (1 << VERT_RESULT_HPOS))) {
          /* the vertex program did not compute a vertex position */
          link_error(shProg,
@@ -466,8 +497,10 @@ _slang_link(GLcontext *ctx,
          return;
       }
    }
-   if (shProg->FragmentProgram)
+   if (shProg->FragmentProgram) {
+      _slang_count_temporaries(&shProg->FragmentProgram->Base);
       _slang_update_inputs_outputs(&shProg->FragmentProgram->Base);
+   }
 
    /* Check that all the varying vars needed by the fragment shader are
     * actually produced by the vertex shader.