the spec is very explicit about treatment of denorm floats and
the behavior is exactly the same for them as it would be for -0 or
+0. This makes our shading code match that behavior.
Signed-off-by: Zack Rusin <za...@vmware.com>
---
src/gallium/auxiliary/draw/draw_pt.c | 4 +++
src/gallium/auxiliary/gallivm/lp_bld_arit.c | 1 +
src/gallium/auxiliary/util/u_math.c | 51 +++++++++++++++++++++++++++
src/gallium/auxiliary/util/u_math.h | 7 ++++
src/gallium/drivers/llvmpipe/lp_rast.c | 2 ++
5 files changed, 65 insertions(+)
diff --git a/src/gallium/auxiliary/draw/draw_pt.c
b/src/gallium/auxiliary/draw/draw_pt.c
index d2fe002..33c673f 100644
--- a/src/gallium/auxiliary/draw/draw_pt.c
+++ b/src/gallium/auxiliary/draw/draw_pt.c
@@ -459,8 +459,10 @@ draw_vbo(struct draw_context *draw,
unsigned instance;
unsigned index_limit;
unsigned count;
+ unsigned fpstate = util_fpstate_get();
struct pipe_draw_info resolved_info;
+ util_fpstate_set_denorms_to_zero(fpstate);
resolve_draw_info(info, &resolved_info);
info = &resolved_info;
@@ -518,6 +520,7 @@ draw_vbo(struct draw_context *draw,
if (index_limit == 0) {
/* one of the buffers is too small to do any valid drawing */
debug_warning("draw: VBO too small to draw anything\n");
+ util_fpstate_set(fpstate);
return;
}
}
@@ -558,4 +561,5 @@ draw_vbo(struct draw_context *draw,
if (draw->collect_statistics) {
draw->render->pipeline_statistics(draw->render, &draw->statistics);
}
+ util_fpstate_set(fpstate);
}
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c
b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
index 08aec79..c006ac5 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c
@@ -62,6 +62,7 @@
#include "lp_bld_debug.h"
#include "lp_bld_bitarit.h"
#include "lp_bld_arit.h"
+#include "lp_bld_flow.h"
#define EXP_POLY_DEGREE 5
diff --git a/src/gallium/auxiliary/util/u_math.c
b/src/gallium/auxiliary/util/u_math.c
index 2811475..70ff710 100644
--- a/src/gallium/auxiliary/util/u_math.c
+++ b/src/gallium/auxiliary/util/u_math.c
@@ -28,6 +28,7 @@
#include "util/u_math.h"
+#include "util/u_cpu_detect.h"
/** 2^x, for x in [-1.0, 1.0) */
@@ -70,4 +71,54 @@ util_init_math(void)
}
}
+/**
+ * Fetches the contents of the fpstate (mxcsr on x86) register.
+ *
+ * On platforms without support for it just returns 0.
+ */
+unsigned
+util_fpstate_get(void)
+{
+ unsigned mxcsr = 0;
+
+#if defined(PIPE_ARCH_X86) || defined(PIPE_ARCH_X86_64)
+ if (util_cpu_caps.has_sse3) {
+ mxcsr = __builtin_ia32_stmxcsr();
+ }
+#endif
+ return mxcsr;
+}
+
+/**
+ * Make sure that the fp treats the denormalized floating
+ * point numbers as zero.
+ */
+unsigned
+util_fpstate_set_denorms_to_zero(unsigned current_mxcsr)
+{
+#if defined(PIPE_ARCH_X86) || defined(PIPE_ARCH_X86_64)
+#define MXCSR_DAZ (1 << 6) /* Enable denormals are zero mode */
+#define MXCSR_FTZ (1 << 15) /* Enable flush to zero mode */
+ if (util_cpu_caps.has_sse3) {
+ current_mxcsr |= MXCSR_DAZ | MXCSR_FTZ;
+ util_fpstate_set(current_mxcsr);
+ }
+#endif
+ return current_mxcsr;
+}
+
+/**
+ * Set the state of the fpstate (mxcsr on x86) register.
+ *
+ * On platforms without support for it's a noop.
+ */
+void
+util_fpstate_set(unsigned mxcsr)
+{
+#if defined(PIPE_ARCH_X86) || defined(PIPE_ARCH_X86_64)
+ if (util_cpu_caps.has_sse3) {
+ __builtin_ia32_ldmxcsr(mxcsr);
+ }
+#endif
+}
diff --git a/src/gallium/auxiliary/util/u_math.h
b/src/gallium/auxiliary/util/u_math.h
index 64d16cb..bc39488 100644
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -763,6 +763,13 @@ static INLINE int32_t util_signed_fixed(float value,
unsigned frac_bits)
return (int32_t)(value * (1<<frac_bits));
}
+unsigned
+util_fpstate_get(void);
+unsigned
+util_fpstate_set_denorms_to_zero(unsigned current_fpstate);
+void
+util_fpstate_set(unsigned fpstate);
+
#ifdef __cplusplus
diff --git a/src/gallium/drivers/llvmpipe/lp_rast.c
b/src/gallium/drivers/llvmpipe/lp_rast.c
index 871cc50..536f916 100644
--- a/src/gallium/drivers/llvmpipe/lp_rast.c
+++ b/src/gallium/drivers/llvmpipe/lp_rast.c
@@ -751,6 +751,8 @@ static PIPE_THREAD_ROUTINE( thread_function, init_data )
struct lp_rasterizer_task *task = (struct lp_rasterizer_task *) init_data;
struct lp_rasterizer *rast = task->rast;
boolean debug = false;
+ unsigned fpstate = util_fpstate_get();
+ util_fpstate_set_denorms_to_zero(fpstate);
while (1) {
/* wait for work */
--
1.7.10.4
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