From 9017d37e84771f921a63676dd8b955df9ef20f29 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Fri, 23 Jan 2026 10:07:27 -0800 Subject: [PATCH] nir: Use STACK_ARRAY instead of NIR_VLA The number of fields comes from the shader, so it could be a value large enough that using alloca would be problematic. Fixes: c11833ab24d ("nir,spirv: Rework function calls") Reviewed-by: Caio Oliveira Reviewed-by: Ryan Neph Reviewed-by: Lionel Landwerlin Part-of: --- src/compiler/nir/nir_functions.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) Index: mesa-23.3.4/src/compiler/nir/nir_functions.c =================================================================== --- mesa-23.3.4.orig/src/compiler/nir/nir_functions.c +++ mesa-23.3.4/src/compiler/nir/nir_functions.c @@ -24,7 +24,24 @@ #include "nir.h" #include "nir_builder.h" #include "nir_control_flow.h" -#include "nir_vla.h" + +#include + +#define STACK_ARRAY_SIZE 8 + +/* Sometimes gcc may claim -Wmaybe-uninitialized for the stack array in some + * places it can't verify that when size is 0 nobody down the call chain reads + * the array. Please don't try to fix it by zero-initializing the array here + * since it's used in a lot of different places. An "if (size == 0) return;" + * may work for you. + */ +#define STACK_ARRAY(type, name, size) \ + type _stack_##name[STACK_ARRAY_SIZE]; \ + type *const name = \ + ((size) <= STACK_ARRAY_SIZE ? _stack_##name : (type *)malloc((size) * sizeof(type))) + +#define STACK_ARRAY_FINISH(name) \ + if (name != _stack_##name) free(name) /* * TODO: write a proper inliner for GPUs. @@ -177,12 +194,13 @@ static bool inline_functions_pass(nir_bu * to an SSA value first. */ const unsigned num_params = call->num_params; - NIR_VLA(nir_def *, params, num_params); + STACK_ARRAY(nir_def *, params, num_params); for (unsigned i = 0; i < num_params; i++) { params[i] = call->params[i].ssa; } nir_inline_function_impl(b, call->callee->impl, params, NULL); + STACK_ARRAY_FINISH(params); return true; }