nvc0: do upload-time fixups for interpolation parameters

Unfortunately flatshading is an all-or-nothing proposition on nvc0,
while GL 3.0 calls for the ability to selectively specify explicit
interpolation parameters on gl_Color/gl_SecondaryColor which would
override the flatshading setting. This allows us to fix up the
interpolation settings after shader generation based on rasterizer
settings.

While we're at it, we can add support for dynamically forcing all
(non-flat) shader inputs to be interpolated per-sample, which allows
st/mesa to not generate variants for these.

Fixes the remaining failing glsl-1.30/execution/interpolation piglits.

Signed-off-by: Ilia Mirkin <[email protected]>

15 files changed, 239 insertions, 19 deletions

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_driver.h b/src/gallium/drivers/nouveau/codegen/nv50_ir_driver.h
index 2b9edcf9172..3cc467fdb13 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_driver.h
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_driver.h
@@ -99,6 +99,7 @@ struct nv50_ir_prog_info
       uint8_t sourceRep;  /* NV50_PROGRAM_IR */
       const void *source;
       void *relocData;
+      void *interpData;
       struct nv50_ir_prog_symbol *syms;
       uint16_t numSyms;
    } bin;
@@ -198,6 +199,10 @@ extern void nv50_ir_relocate_code(void *relocData, uint32_t *code,
                                   uint32_t libPos,
                                   uint32_t dataPos);
 
+extern void
+nv50_ir_change_interp(void *interpData, uint32_t *code,
+                      bool force_per_sample, bool flatshade);
+
 /* obtain code that will be shared among programs */
 extern void nv50_ir_get_target_library(uint32_t chipset,
                                        const uint32_t **code, uint32_t *size);
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
index 8f1542959c9..d712c9c300a 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
@@ -1437,6 +1437,30 @@ CodeEmitterGK110::emitInterpMode(const Instruction *i)
    code[1] |= (i->ipa & 0xc) << (19 - 2);
 }
 
+static void
+interpApply(const InterpEntry *entry, uint32_t *code,
+      bool force_persample_interp, bool flatshade)
+{
+   int ipa = entry->ipa;
+   int reg = entry->reg;
+   int loc = entry->loc;
+
+   if (flatshade &&
+       (ipa & NV50_IR_INTERP_MODE_MASK) == NV50_IR_INTERP_SC) {
+      ipa = NV50_IR_INTERP_FLAT;
+      reg = 0xff;
+   } else if (force_persample_interp &&
+              (ipa & NV50_IR_INTERP_SAMPLE_MASK) == NV50_IR_INTERP_DEFAULT &&
+              (ipa & NV50_IR_INTERP_MODE_MASK) != NV50_IR_INTERP_FLAT) {
+      ipa |= NV50_IR_INTERP_CENTROID;
+   }
+   code[loc + 1] &= ~(0xf << 19);
+   code[loc + 1] |= (ipa & 0x3) << 21;
+   code[loc + 1] |= (ipa & 0xc) << (19 - 2);
+   code[loc + 0] &= ~(0xff << 23);
+   code[loc + 0] |= reg << 23;
+}
+
 void
 CodeEmitterGK110::emitINTERP(const Instruction *i)
 {
@@ -1448,10 +1472,13 @@ CodeEmitterGK110::emitINTERP(const Instruction *i)
    if (i->saturate)
       code[1] |= 1 << 18;
 
-   if (i->op == OP_PINTERP)
+   if (i->op == OP_PINTERP) {
       srcId(i->src(1), 23);
-   else
+      addInterp(i->ipa, SDATA(i->src(1)).id, interpApply);
+   } else {
       code[0] |= 0xff << 23;
+      addInterp(i->ipa, 0xff, interpApply);
+   }
 
    srcId(i->src(0).getIndirect(0), 10);
    emitInterpMode(i);
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
index 6e22788341f..a327d572470 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
@@ -2217,6 +2217,30 @@ CodeEmitterGM107::emitAL2P()
    emitGPR  (0x00, insn->def(0));
 }
 
+static void
+interpApply(const InterpEntry *entry, uint32_t *code,
+      bool force_persample_interp, bool flatshade)
+{
+   int ipa = entry->ipa;
+   int reg = entry->reg;
+   int loc = entry->loc;
+
+   if (flatshade &&
+       (ipa & NV50_IR_INTERP_MODE_MASK) == NV50_IR_INTERP_SC) {
+      ipa = NV50_IR_INTERP_FLAT;
+      reg = 0xff;
+   } else if (force_persample_interp &&
+              (ipa & NV50_IR_INTERP_SAMPLE_MASK) == NV50_IR_INTERP_DEFAULT &&
+              (ipa & NV50_IR_INTERP_MODE_MASK) != NV50_IR_INTERP_FLAT) {
+      ipa |= NV50_IR_INTERP_CENTROID;
+   }
+   code[loc + 1] &= ~(0xf << 0x14);
+   code[loc + 1] |= (ipa & 0x3) << 0x16;
+   code[loc + 1] |= (ipa & 0xc) << (0x14 - 2);
+   code[loc + 0] &= ~(0xff << 0x14);
+   code[loc + 0] |= reg << 0x14;
+}
+
 void
 CodeEmitterGM107::emitIPA()
 {
@@ -2255,10 +2279,12 @@ CodeEmitterGM107::emitIPA()
       emitGPR(0x14, insn->src(1));
       if (insn->getSampleMode() == NV50_IR_INTERP_OFFSET)
          emitGPR(0x27, insn->src(2));
+      addInterp(insn->ipa, insn->getSrc(1)->reg.data.id, interpApply);
    } else {
       if (insn->getSampleMode() == NV50_IR_INTERP_OFFSET)
          emitGPR(0x27, insn->src(1));
       emitGPR(0x14);
+      addInterp(insn->ipa, 0xff, interpApply);
    }
 
    if (insn->getSampleMode() != NV50_IR_INTERP_OFFSET)
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nvc0.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nvc0.cpp
index 6bf5219d346..fd103146c72 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nvc0.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nvc0.cpp
@@ -1618,6 +1618,29 @@ CodeEmitterNVC0::emitInterpMode(const Instruction *i)
    }
 }
 
+static void
+interpApply(const InterpEntry *entry, uint32_t *code,
+      bool force_persample_interp, bool flatshade)
+{
+   int ipa = entry->ipa;
+   int reg = entry->reg;
+   int loc = entry->loc;
+
+   if (flatshade &&
+       (ipa & NV50_IR_INTERP_MODE_MASK) == NV50_IR_INTERP_SC) {
+      ipa = NV50_IR_INTERP_FLAT;
+      reg = 0x3f;
+   } else if (force_persample_interp &&
+              (ipa & NV50_IR_INTERP_SAMPLE_MASK) == NV50_IR_INTERP_DEFAULT &&
+              (ipa & NV50_IR_INTERP_MODE_MASK) != NV50_IR_INTERP_FLAT) {
+      ipa |= NV50_IR_INTERP_CENTROID;
+   }
+   code[loc + 0] &= ~(0xf << 6);
+   code[loc + 0] |= ipa << 6;
+   code[loc + 0] &= ~(0x3f << 26);
+   code[loc + 0] |= reg << 26;
+}
+
 void
 CodeEmitterNVC0::emitINTERP(const Instruction *i)
 {
@@ -1630,10 +1653,13 @@ CodeEmitterNVC0::emitINTERP(const Instruction *i)
       if (i->saturate)
          code[0] |= 1 << 5;
 
-      if (i->op == OP_PINTERP)
+      if (i->op == OP_PINTERP) {
          srcId(i->src(1), 26);
-      else
+         addInterp(i->ipa, SDATA(i->src(1)).id, interpApply);
+      } else {
          code[0] |= 0x3f << 26;
+         addInterp(i->ipa, 0x3f, interpApply);
+      }
 
       srcId(i->src(0).getIndirect(0), 20);
    } else {
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
index c8efaf5947a..f27a78e715d 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
@@ -1054,7 +1054,7 @@ bool Source::scanDeclaration(const struct tgsi_full_declaration *decl)
                default:
                   break;
                }
-               if (decl->Interp.Location || info->io.sampleInterp)
+               if (decl->Interp.Location)
                   info->in[i].centroid = 1;
             }
 
@@ -1119,6 +1119,10 @@ bool Source::scanDeclaration(const struct tgsi_full_declaration *decl)
       case TGSI_SEMANTIC_VERTEXID:
          info->io.vertexId = first;
          break;
+      case TGSI_SEMANTIC_SAMPLEID:
+      case TGSI_SEMANTIC_SAMPLEPOS:
+         info->io.sampleInterp = 1;
+         break;
       default:
          break;
       }
@@ -1338,6 +1342,8 @@ private:
 
    void handleINTERP(Value *dst0[4]);
 
+   uint8_t translateInterpMode(const struct nv50_ir_varying *var,
+                               operation& op);
    Value *interpolate(tgsi::Instruction::SrcRegister, int c, Value *ptr);
 
    void insertConvergenceOps(BasicBlock *conv, BasicBlock *fork);
@@ -1451,8 +1457,8 @@ Converter::makeSym(uint tgsiFile, int fileIdx, int idx, int c, uint32_t address)
    return sym;
 }
 
-static inline uint8_t
-translateInterpMode(const struct nv50_ir_varying *var, operation& op)
+uint8_t
+Converter::translateInterpMode(const struct nv50_ir_varying *var, operation& op)
 {
    uint8_t mode = NV50_IR_INTERP_PERSPECTIVE;
 
@@ -1468,7 +1474,7 @@ translateInterpMode(const struct nv50_ir_varying *var, operation& op)
    op = (mode == NV50_IR_INTERP_PERSPECTIVE || mode == NV50_IR_INTERP_SC)
       ? OP_PINTERP : OP_LINTERP;
 
-   if (var->centroid)
+   if (var->centroid || info->io.sampleInterp)
       mode |= NV50_IR_INTERP_CENTROID;
 
    return mode;
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_target.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_target.cpp
index fe530c76b62..afc8ff1374f 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_target.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_target.cpp
@@ -166,7 +166,7 @@ void Target::destroy(Target *targ)
    delete targ;
 }
 
-CodeEmitter::CodeEmitter(const Target *target) : targ(target)
+CodeEmitter::CodeEmitter(const Target *target) : targ(target), interpInfo(NULL)
 {
 }
 
@@ -388,6 +388,7 @@ Program::emitBinary(struct nv50_ir_prog_info *info)
       }
    }
    info->bin.relocData = emit->getRelocInfo();
+   info->bin.interpData = emit->getInterpInfo();
 
    emitSymbolTable(info);
 
@@ -428,6 +429,29 @@ CodeEmitter::addReloc(RelocEntry::Type ty, int w, uint32_t data, uint32_t m,
    return true;
 }
 
+bool
+CodeEmitter::addInterp(int ipa, int reg, InterpApply apply)
+{
+   unsigned int n = interpInfo ? interpInfo->count : 0;
+
+   if (!(n % RELOC_ALLOC_INCREMENT)) {
+      size_t size = sizeof(InterpInfo) + n * sizeof(InterpEntry);
+      interpInfo = reinterpret_cast<InterpInfo *>(
+         REALLOC(interpInfo, n ? size : 0,
+                 size + RELOC_ALLOC_INCREMENT * sizeof(InterpEntry)));
+      if (!interpInfo)
+         return false;
+      if (n == 0)
+         memset(interpInfo, 0, sizeof(InterpInfo));
+   }
+   ++interpInfo->count;
+
+   interpInfo->entry[n] = InterpEntry(ipa, reg, codeSize >> 2);
+   interpInfo->apply = apply;
+
+   return true;
+}
+
 void
 RelocEntry::apply(uint32_t *binary, const RelocInfo *info) const
 {
@@ -472,6 +496,19 @@ nv50_ir_relocate_code(void *relocData, uint32_t *code,
 }
 
 void
+nv50_ir_change_interp(void *interpData, uint32_t *code,
+                      bool force_persample_interp, bool flatshade)
+{
+   nv50_ir::InterpInfo *info = reinterpret_cast<nv50_ir::InterpInfo *>(
+      interpData);
+
+   // force_persample_interp: all non-flat -> per-sample
+   // flatshade: all color -> flat
+   for (unsigned i = 0; i < info->count; ++i)
+      info->apply(&info->entry[i], code, force_persample_interp, flatshade);
+}
+
+void
 nv50_ir_get_target_library(uint32_t chipset,
                            const uint32_t **code, uint32_t *size)
 {
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_target.h b/src/gallium/drivers/nouveau/codegen/nv50_ir_target.h
index 591916eb412..4e33997e1c1 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_target.h
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_target.h
@@ -58,6 +58,23 @@ struct RelocInfo
    RelocEntry entry[0];
 };
 
+struct InterpEntry
+{
+   InterpEntry(int ipa, int reg, int loc) : ipa(ipa), reg(reg), loc(loc) {}
+   uint32_t ipa:4; // SC mode used to identify colors
+   uint32_t reg:8; // The reg used for perspective division
+   uint32_t loc:20; // Let's hope we don't have more than 1M-sized shaders
+};
+
+typedef void (*InterpApply)(const InterpEntry*, uint32_t*, bool, bool);
+
+struct InterpInfo
+{
+   uint32_t count;
+   InterpApply apply;
+   InterpEntry entry[0];
+};
+
 class CodeEmitter
 {
 public:
@@ -78,6 +95,9 @@ public:
 
    inline void *getRelocInfo() const { return relocInfo; }
 
+   bool addInterp(int ipa, int reg, InterpApply apply);
+   inline void *getInterpInfo() const { return interpInfo; }
+
    virtual void prepareEmission(Program *);
    virtual void prepareEmission(Function *);
    virtual void prepareEmission(BasicBlock *);
@@ -92,6 +112,7 @@ protected:
    uint32_t codeSizeLimit;
 
    RelocInfo *relocInfo;
+   InterpInfo *interpInfo;
 };
 
 
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_program.c b/src/gallium/drivers/nouveau/nvc0/nvc0_program.c
index a168dd684ab..b70b08a4a1e 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_program.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_program.c
@@ -424,6 +424,11 @@ nvc0_fp_gen_header(struct nvc0_program *fp, struct nv50_ir_prog_info *info)
 
    for (i = 0; i < info->numInputs; ++i) {
       m = nvc0_hdr_interp_mode(&info->in[i]);
+      if (info->in[i].sn == TGSI_SEMANTIC_COLOR) {
+         fp->fp.colors |= 1 << info->in[i].si;
+         if (info->in[i].sc)
+            fp->fp.color_interp[info->in[i].si] = m | (info->in[i].mask << 4);
+      }
       for (c = 0; c < 4; ++c) {
          if (!(info->in[i].mask & (1 << c)))
             continue;
@@ -531,7 +536,6 @@ nvc0_program_translate(struct nvc0_program *prog, uint16_t chipset)
    info->io.genUserClip = prog->vp.num_ucps;
    info->io.ucpBase = 256;
    info->io.ucpCBSlot = 15;
-   info->io.sampleInterp = prog->fp.sample_interp;
 
    if (prog->type == PIPE_SHADER_COMPUTE) {
       if (chipset >= NVISA_GK104_CHIPSET) {
@@ -575,6 +579,7 @@ nvc0_program_translate(struct nvc0_program *prog, uint16_t chipset)
    prog->immd_data = info->immd.buf;
    prog->immd_size = info->immd.bufSize;
    prog->relocs = info->bin.relocData;
+   prog->interps = info->bin.interpData;
    prog->num_gprs = MAX2(4, (info->bin.maxGPR + 1));
    prog->num_barriers = info->numBarriers;
 
@@ -713,6 +718,23 @@ nvc0_program_upload_code(struct nvc0_context *nvc0, struct nvc0_program *prog)
 
    if (prog->relocs)
       nv50_ir_relocate_code(prog->relocs, prog->code, code_pos, lib_pos, 0);
+   if (prog->interps) {
+      nv50_ir_change_interp(prog->interps, prog->code,
+                            prog->fp.force_persample_interp,
+                            prog->fp.flatshade);
+      for (int i = 0; i < 2; i++) {
+         unsigned mask = prog->fp.color_interp[i] >> 4;
+         unsigned interp = prog->fp.color_interp[i] & 3;
+         if (!mask)
+            continue;
+         prog->hdr[14] &= ~(0xff << (8 * i));
+         if (prog->fp.flatshade)
+            interp = NVC0_INTERP_FLAT;
+         for (int c = 0; c < 4; c++)
+            if (mask & (1 << c))
+               prog->hdr[14] |= interp << (2 * (4 * i + c));
+      }
+   }
 
 #ifdef DEBUG
    if (debug_get_bool_option("NV50_PROG_DEBUG", false))
@@ -773,6 +795,7 @@ nvc0_program_destroy(struct nvc0_context *nvc0, struct nvc0_program *prog)
    FREE(prog->code); /* may be 0 for hardcoded shaders */
    FREE(prog->immd_data);
    FREE(prog->relocs);
+   FREE(prog->interps);
    if (prog->type == PIPE_SHADER_COMPUTE && prog->cp.syms)
       FREE(prog->cp.syms);
    if (prog->tfb) {
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_program.h b/src/gallium/drivers/nouveau/nvc0/nvc0_program.h
index 390e0c7a4f0..9c45e7b3e31 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_program.h
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_program.h
@@ -45,8 +45,10 @@ struct nvc0_program {
    } vp;
    struct {
       uint8_t early_z;
-      uint8_t in_pos[PIPE_MAX_SHADER_INPUTS];
-      uint8_t sample_interp;
+      uint8_t colors;
+      uint8_t color_interp[2];
+      bool force_persample_interp;
+      bool flatshade;
    } fp;
    struct {
       uint32_t tess_mode; /* ~0 if defined by the other stage */
@@ -61,6 +63,7 @@ struct nvc0_program {
    uint8_t num_barriers;
 
    void *relocs;
+   void *interps;
 
    struct nvc0_transform_feedback_state *tfb;
 
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
index 422d6d45369..d48c32d2b93 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.c
@@ -180,6 +180,7 @@ nvc0_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_DEPTH_BOUNDS_TEST:
    case PIPE_CAP_TGSI_TXQS:
    case PIPE_CAP_COPY_BETWEEN_COMPRESSED_AND_PLAIN_FORMATS:
+   case PIPE_CAP_FORCE_PERSAMPLE_INTERP:
       return 1;
    case PIPE_CAP_SEAMLESS_CUBE_MAP_PER_TEXTURE:
       return (class_3d >= NVE4_3D_CLASS) ? 1 : 0;
@@ -202,7 +203,6 @@ nvc0_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_VERTEXID_NOBASE:
    case PIPE_CAP_RESOURCE_FROM_USER_MEMORY:
    case PIPE_CAP_DEVICE_RESET_STATUS_QUERY:
-   case PIPE_CAP_FORCE_PERSAMPLE_INTERP:
    case PIPE_CAP_SHAREABLE_SHADERS:
       return 0;
 
@@ -828,6 +828,8 @@ nvc0_screen_create(struct nouveau_device *dev)
    PUSH_DATA (push, 1);
    BEGIN_NVC0(push, NVC0_3D(BLEND_ENABLE_COMMON), 1);
    PUSH_DATA (push, 0);
+   BEGIN_NVC0(push, NVC0_3D(SHADE_MODEL), 1);
+   PUSH_DATA (push, NVC0_3D_SHADE_MODEL_SMOOTH);
    if (screen->eng3d->oclass < NVE4_3D_CLASS) {
       BEGIN_NVC0(push, NVC0_3D(TEX_MISC), 1);
       PUSH_DATA (push, NVC0_3D_TEX_MISC_SEAMLESS_CUBE_MAP);
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.h b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.h
index 857eb0316c7..8b73102b98b 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_screen.h
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_screen.h
@@ -38,6 +38,7 @@ struct nvc0_graph_state {
    uint32_t constant_elts;
    int32_t index_bias;
    uint16_t scissor;
+   bool flatshade;
    uint8_t patch_vertices;
    uint8_t vbo_mode; /* 0 = normal, 1 = translate, 3 = translate, forced */
    uint8_t num_vtxbufs;
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_shader_state.c b/src/gallium/drivers/nouveau/nvc0/nvc0_shader_state.c
index af837fc4a33..8595800592c 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_shader_state.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_shader_state.c
@@ -107,8 +107,54 @@ nvc0_fragprog_validate(struct nvc0_context *nvc0)
 {
    struct nouveau_pushbuf *push = nvc0->base.pushbuf;
    struct nvc0_program *fp = nvc0->fragprog;
+   struct pipe_rasterizer_state *rast = &nvc0->rast->pipe;
 
-   fp->fp.sample_interp = nvc0->min_samples > 1;
+   if (fp->fp.force_persample_interp != rast->force_persample_interp) {
+      /* Force the program to be reuploaded, which will trigger interp fixups
+       * to get applied
+       */
+      if (fp->mem)
+         nouveau_heap_free(&fp->mem);
+
+      fp->fp.force_persample_interp = rast->force_persample_interp;
+   }
+
+   /* Shade model works well enough when both colors follow it. However if one
+    * (or both) is explicitly set, then we have to go the patching route.
+    */
+   bool has_explicit_color = fp->fp.colors &&
+      (((fp->fp.colors & 1) && !fp->fp.color_interp[0]) ||
+       ((fp->fp.colors & 2) && !fp->fp.color_interp[1]));
+   bool hwflatshade = false;
+   if (has_explicit_color && fp->fp.flatshade != rast->flatshade) {
+      /* Force re-upload */
+      if (fp->mem)
+         nouveau_heap_free(&fp->mem);
+
+      fp->fp.flatshade = rast->flatshade;
+
+      /* Always smooth-shade in this mode, the shader will decide on its own
+       * when to flat-shade.
+       */
+   } else if (!has_explicit_color) {
+      hwflatshade = rast->flatshade;
+
+      /* No need to binary-patch the shader each time, make sure that it's set
+       * up for the default behaviour.
+       */
+      fp->fp.flatshade = 0;
+   }
+
+   if (hwflatshade != nvc0->state.flatshade) {
+      nvc0->state.flatshade = hwflatshade;
+      BEGIN_NVC0(push, NVC0_3D(SHADE_MODEL), 1);
+      PUSH_DATA (push, hwflatshade ? NVC0_3D_SHADE_MODEL_FLAT :
+                                     NVC0_3D_SHADE_MODEL_SMOOTH);
+   }
+
+   if (fp->mem && !(nvc0->dirty & NVC0_NEW_FRAGPROG)) {
+      return;
+   }
 
    if (!nvc0_program_validate(nvc0, fp))
          return;
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_state.c b/src/gallium/drivers/nouveau/nvc0/nvc0_state.c
index 742bef39247..e95554df12e 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_state.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_state.c
@@ -212,9 +212,6 @@ nvc0_rasterizer_state_create(struct pipe_context *pipe,
      * always emit 16 commands, one for each scissor rectangle, here.
      */
 
-    SB_BEGIN_3D(so, SHADE_MODEL, 1);
-    SB_DATA    (so, cso->flatshade ? NVC0_3D_SHADE_MODEL_FLAT :
-                                     NVC0_3D_SHADE_MODEL_SMOOTH);
     SB_IMMED_3D(so, PROVOKING_VERTEX_LAST, !cso->flatshade_first);
     SB_IMMED_3D(so, VERTEX_TWO_SIDE_ENABLE, cso->light_twoside);
 
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_state_validate.c b/src/gallium/drivers/nouveau/nvc0/nvc0_state_validate.c
index aec06097bbd..f86de31c889 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_state_validate.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_state_validate.c
@@ -645,7 +645,7 @@ static struct state_validate {
     { nvc0_tevlprog_validate,      NVC0_NEW_TEVLPROG },
     { nvc0_validate_tess_state,    NVC0_NEW_TESSFACTOR },
     { nvc0_gmtyprog_validate,      NVC0_NEW_GMTYPROG },
-    { nvc0_fragprog_validate,      NVC0_NEW_FRAGPROG },
+    { nvc0_fragprog_validate,      NVC0_NEW_FRAGPROG | NVC0_NEW_RASTERIZER },
     { nvc0_validate_derived_1,     NVC0_NEW_FRAGPROG | NVC0_NEW_ZSA |
                                    NVC0_NEW_RASTERIZER },
     { nvc0_validate_derived_2,     NVC0_NEW_ZSA | NVC0_NEW_FRAMEBUFFER },
diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_stateobj.h b/src/gallium/drivers/nouveau/nvc0/nvc0_stateobj.h
index 8bc33c6a0e0..f9680f5a90f 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_stateobj.h
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_stateobj.h
@@ -23,7 +23,7 @@ struct nvc0_blend_stateobj {
 struct nvc0_rasterizer_stateobj {
    struct pipe_rasterizer_state pipe;
    int size;
-   uint32_t state[44];
+   uint32_t state[42];
 };
 
 struct nvc0_zsa_stateobj {