diff options
Diffstat (limited to 'src/gallium/drivers/radeonsi/si_shader.c')
| -rw-r--r-- | src/gallium/drivers/radeonsi/si_shader.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c index 7adf76a0b03..0bda187cfd2 100644 --- a/src/gallium/drivers/radeonsi/si_shader.c +++ b/src/gallium/drivers/radeonsi/si_shader.c @@ -1401,9 +1401,22 @@ static void declare_system_value(struct si_shader_context *ctx, break; case TGSI_SEMANTIC_BASEVERTEX: - value = LLVMGetParam(ctx->main_fn, - SI_PARAM_BASE_VERTEX); + { + /* For non-indexed draws, the base vertex set by the driver + * (for direct draws) or the CP (for indirect draws) is the + * first vertex ID, but GLSL expects 0 to be returned. + */ + LLVMValueRef vs_state = LLVMGetParam(ctx->main_fn, SI_PARAM_VS_STATE_BITS); + LLVMValueRef indexed; + + indexed = LLVMBuildLShr(gallivm->builder, vs_state, ctx->i32_1, ""); + indexed = LLVMBuildTrunc(gallivm->builder, indexed, ctx->i1, ""); + + value = LLVMBuildSelect(gallivm->builder, indexed, + LLVMGetParam(ctx->main_fn, SI_PARAM_BASE_VERTEX), + ctx->i32_0, ""); break; + } case TGSI_SEMANTIC_BASEINSTANCE: value = LLVMGetParam(ctx->main_fn, |