MSL: Allow removing clip distance user varyings.

Only safe if user knows that subsequent shader stage will not read clip
distance.

3 files changed, 70 insertions, 0 deletions

diff --git a/reference/opt/shaders-msl/asm/vert/clip-distance-plain-variable.no-user-varying.asm.vert b/reference/opt/shaders-msl/asm/vert/clip-distance-plain-variable.no-user-varying.asm.vert
new file mode 100644
index 00000000..1d688595
--- /dev/null
+++ b/reference/opt/shaders-msl/asm/vert/clip-distance-plain-variable.no-user-varying.asm.vert
@@ -0,0 +1,25 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct main0_out
+{
+    float4 gl_Position [[position]];
+    float gl_ClipDistance [[clip_distance]] [2];
+};
+
+struct main0_in
+{
+    float4 pos [[attribute(0)]];
+};
+
+vertex main0_out main0(main0_in in [[stage_in]])
+{
+    main0_out out = {};
+    out.gl_Position = in.pos;
+    out.gl_ClipDistance[0] = in.pos.x;
+    out.gl_ClipDistance[1] = in.pos.y;
+    return out;
+}
+
diff --git a/reference/opt/shaders-msl/desktop-only/vert/clip-cull-distance..no-user-varying.desktop.vert b/reference/opt/shaders-msl/desktop-only/vert/clip-cull-distance..no-user-varying.desktop.vert
new file mode 100644
index 00000000..a414c985
--- /dev/null
+++ b/reference/opt/shaders-msl/desktop-only/vert/clip-cull-distance..no-user-varying.desktop.vert
@@ -0,0 +1,20 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct main0_out
+{
+    float4 gl_Position [[position]];
+    float gl_ClipDistance [[clip_distance]] [2];
+};
+
+vertex main0_out main0()
+{
+    main0_out out = {};
+    out.gl_Position = float4(10.0);
+    out.gl_ClipDistance[0] = 1.0;
+    out.gl_ClipDistance[1] = 4.0;
+    return out;
+}
+
diff --git a/reference/opt/shaders-msl/vert/clip-distance-block.no-user-varying.vert b/reference/opt/shaders-msl/vert/clip-distance-block.no-user-varying.vert
new file mode 100644
index 00000000..c78105e0
--- /dev/null
+++ b/reference/opt/shaders-msl/vert/clip-distance-block.no-user-varying.vert
@@ -0,0 +1,25 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct main0_out
+{
+    float4 gl_Position [[position]];
+    float gl_ClipDistance [[clip_distance]] [2];
+};
+
+struct main0_in
+{
+    float4 Position [[attribute(0)]];
+};
+
+vertex main0_out main0(main0_in in [[stage_in]])
+{
+    main0_out out = {};
+    out.gl_Position = in.Position;
+    out.gl_ClipDistance[0] = in.Position.x;
+    out.gl_ClipDistance[1] = in.Position.y;
+    return out;
+}
+