3 files changed, 21 insertions, 1 deletions
diff --git a/src/gallium/drivers/swr/rasterizer/core/backend_impl.h b/src/gallium/drivers/swr/rasterizer/core/backend_impl.h
index 1bd2e743781..c6f3b0242c8 100644
--- a/src/gallium/drivers/swr/rasterizer/core/backend_impl.h
+++ b/src/gallium/drivers/swr/rasterizer/core/backend_impl.h
@@ -29,6 +29,9 @@
 #pragma once
 
 #include "tilemgr.h"
+#include "state.h"
+#include "context.h"
+
 
 void InitBackendSingleFuncTable(PFN_BACKEND_FUNC (&table)[SWR_INPUT_COVERAGE_COUNT][2][2]);
 void InitBackendSampleFuncTable(
@@ -648,6 +651,7 @@ void SetupPixelShaderContext(SWR_PS_CONTEXT*            psContext,
     psContext->pPerspAttribs          = work.pPerspAttribs;
     psContext->frontFace              = work.triFlags.frontFacing;
     psContext->renderTargetArrayIndex = work.triFlags.renderTargetArrayIndex;
+    psContext->viewportIndex          = work.triFlags.viewportIndex;
 
     // save Ia/Ib/Ic and Ja/Jb/Jc if we need to reevaluate i/j/k in the shader because of pull
     // attribs
diff --git a/src/gallium/drivers/swr/rasterizer/core/state.h b/src/gallium/drivers/swr/rasterizer/core/state.h
index 25d4fed9578..66144bbef75 100644
--- a/src/gallium/drivers/swr/rasterizer/core/state.h
+++ b/src/gallium/drivers/swr/rasterizer/core/state.h
@@ -387,6 +387,7 @@ struct SWR_PS_CONTEXT
     uint32_t frontFace;              // IN: front- 1, back- 0
     uint32_t sampleIndex;            // IN: sampleIndex
     uint32_t renderTargetArrayIndex; // IN: render target array index from GS
+    uint32_t viewportIndex;          // IN: viewport index from GS
     uint32_t rasterizerSampleCount;  // IN: sample count used by the rasterizer
 
     uint8_t* pColorBuffer[SWR_NUM_RENDERTARGETS]; // IN: Pointers to render target hottiles
diff --git a/src/gallium/drivers/swr/swr_shader.cpp b/src/gallium/drivers/swr/swr_shader.cpp
index 44fc133f530..cbffaef0b12 100644
--- a/src/gallium/drivers/swr/swr_shader.cpp
+++ b/src/gallium/drivers/swr/swr_shader.cpp
@@ -1170,8 +1170,23 @@ BuilderSWR::CompileFS(struct swr_context *ctx, swr_jit_fs_key &key)
          inputs[attrib][3] =
             wrap(LOAD(pPS, {0, SWR_PS_CONTEXT_vOneOverW, PixelPositions_center}, "vOneOverW"));
          continue;
+      } else if (semantic_name == TGSI_SEMANTIC_LAYER) { // gl_Layer
+         Value *ff = LOAD(pPS, {0, SWR_PS_CONTEXT_renderTargetArrayIndex});
+         ff = VECTOR_SPLAT(JM()->mVWidth, ff, "vRenderTargetArrayIndex");
+         inputs[attrib][0] = wrap(ff);
+         inputs[attrib][1] = wrap(VIMMED1(0.0f));
+         inputs[attrib][2] = wrap(VIMMED1(0.0f));
+         inputs[attrib][3] = wrap(VIMMED1(0.0f));
+         continue;
+      } else if (semantic_name == TGSI_SEMANTIC_VIEWPORT_INDEX) { // gl_ViewportIndex
+         Value *ff = LOAD(pPS, {0, SWR_PS_CONTEXT_viewportIndex});
+         ff = VECTOR_SPLAT(JM()->mVWidth, ff, "vViewportIndex");
+         inputs[attrib][0] = wrap(ff);
+         inputs[attrib][1] = wrap(VIMMED1(0.0f));
+         inputs[attrib][2] = wrap(VIMMED1(0.0f));
+         inputs[attrib][3] = wrap(VIMMED1(0.0f));
+         continue;
       }
-
       unsigned linkedAttrib =
          locate_linkage(semantic_name, semantic_idx, pPrevShader) - 1;