[PATCH vkd3d 2/7] vkd3d-shader/hlsl: Make pre/post decrement generate a signed one.

[Giovanni Mascellani]

If a float expression is pre/post decremented and an unsigned one is
used to execute it, the unsigned one is first negated (becoming 2^32-1)
and then casted to float (becoming 2^32), which leads to an incorrect
result.
---
 Makefile.am              |  1 -
 libs/vkd3d-shader/hlsl.c | 12 ++++++++++++
 libs/vkd3d-shader/hlsl.h |  2 ++
 libs/vkd3d-shader/hlsl.y |  2 +-
 4 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 3e083b0a..bbfd6d9c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -303,7 +303,6 @@ XFAIL_TESTS = \
 	tests/hlsl-storage-qualifiers.shader_test \
 	tests/hlsl-vector-indexing.shader_test \
 	tests/hlsl-vector-indexing-uniform.shader_test \
-	tests/math.shader_test \
 	tests/max.shader_test \
 	tests/sampler.shader_test \
 	tests/texture-load.shader_test \
diff --git a/libs/vkd3d-shader/hlsl.c b/libs/vkd3d-shader/hlsl.c
index 1eee4278..f6264fdd 100644
--- a/libs/vkd3d-shader/hlsl.c
+++ b/libs/vkd3d-shader/hlsl.c
@@ -553,6 +553,18 @@ struct hlsl_ir_store *hlsl_new_simple_store(struct hlsl_ctx *ctx, struct hlsl_ir
     return hlsl_new_store(ctx, lhs, NULL, rhs, 0, rhs->loc);
 }
 
+struct hlsl_ir_constant *hlsl_new_int_constant(struct hlsl_ctx *ctx, int n,
+        const struct vkd3d_shader_location loc)
+{
+    struct hlsl_ir_constant *c;
+
+    if (!(c = hlsl_alloc(ctx, sizeof(*c))))
+        return NULL;
+    init_node(&c->node, HLSL_IR_CONSTANT, ctx->builtin_types.scalar[HLSL_TYPE_INT], loc);
+    c->value[0].i = n;
+    return c;
+}
+
 struct hlsl_ir_constant *hlsl_new_uint_constant(struct hlsl_ctx *ctx, unsigned int n,
         const struct vkd3d_shader_location loc)
 {
diff --git a/libs/vkd3d-shader/hlsl.h b/libs/vkd3d-shader/hlsl.h
index 365ef980..3e7c906d 100644
--- a/libs/vkd3d-shader/hlsl.h
+++ b/libs/vkd3d-shader/hlsl.h
@@ -718,6 +718,8 @@ struct hlsl_ir_var *hlsl_new_synthetic_var(struct hlsl_ctx *ctx, const char *nam
 struct hlsl_type *hlsl_new_texture_type(struct hlsl_ctx *ctx, enum hlsl_sampler_dim dim, struct hlsl_type *format);
 struct hlsl_ir_constant *hlsl_new_uint_constant(struct hlsl_ctx *ctx, unsigned int n,
         const struct vkd3d_shader_location loc);
+struct hlsl_ir_constant *hlsl_new_int_constant(struct hlsl_ctx *ctx, int n,
+        const struct vkd3d_shader_location loc);
 struct hlsl_ir_node *hlsl_new_unary_expr(struct hlsl_ctx *ctx, enum hlsl_ir_expr_op op, struct hlsl_ir_node *arg,
         struct vkd3d_shader_location loc);
 struct hlsl_ir_var *hlsl_new_var(struct hlsl_ctx *ctx, const char *name, struct hlsl_type *type,
diff --git a/libs/vkd3d-shader/hlsl.y b/libs/vkd3d-shader/hlsl.y
index b7e0409d..d2bddb2e 100644
--- a/libs/vkd3d-shader/hlsl.y
+++ b/libs/vkd3d-shader/hlsl.y
@@ -1254,7 +1254,7 @@ static bool add_increment(struct hlsl_ctx *ctx, struct list *instrs, bool decrem
         hlsl_error(ctx, loc, VKD3D_SHADER_ERROR_HLSL_MODIFIES_CONST,
                 "Argument to %s%screment operator is const.", post ? "post" : "pre", decrement ? "de" : "in");
 
-    if (!(one = hlsl_new_uint_constant(ctx, 1, loc)))
+    if (!(one = hlsl_new_int_constant(ctx, 1, loc)))
         return false;
     list_add_tail(instrs, &one->node.entry);
 
-- 
2.34.0