[Mesa-dev] [PATCH 2/2] tgsi/lowering: add support to lower CEIL

[Christian Gmeiner]

Signed-off-by: Christian Gmeiner <christian.gmeiner at gmail.com>
---
 src/gallium/auxiliary/tgsi/tgsi_lowering.c | 54 ++++++++++++++++++++++++++++++
 src/gallium/auxiliary/tgsi/tgsi_lowering.h |  1 +
 2 files changed, 55 insertions(+)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_lowering.c b/src/gallium/auxiliary/tgsi/tgsi_lowering.c
index cd5bdc2..54536d1 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_lowering.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_lowering.c
@@ -302,6 +302,50 @@ transform_flr(struct tgsi_transform_context *tctx,
     }
 }
 
+/* CEIL - Ceiling
+ *
+ *   dst.x = \lceil src.x\rceil
+ *   dst.y = \lceil src.y\rceil
+ *   dst.z = \lceil src.z\rceil
+ *   dst.w = \lceil src.w\rceil
+ *
+ * ; needs: 1 tmp
+ * FRC tmpA, src
+ * ADD dst, src, tmpA
+ */
+#define CEIL_GROW (NINST(1) + NINST(2) - OINST(1))
+#define CEIL_TMP  1
+static void
+transform_ceil(struct tgsi_transform_context *tctx,
+              struct tgsi_full_instruction *inst)
+{
+    struct tgsi_lowering_context *ctx = tgsi_lowering_context(tctx);
+    struct tgsi_full_dst_register *dst = &inst->Dst[0];
+    struct tgsi_full_src_register *src = &inst->Src[0];
+    struct tgsi_full_instruction new_inst;
+
+    if (dst->Register.WriteMask & TGSI_WRITEMASK_XYZW) {
+       /* FRC tmpA, src */
+       new_inst = tgsi_default_full_instruction();
+       new_inst.Instruction.Opcode = TGSI_OPCODE_FRC;
+       new_inst.Instruction.NumDstRegs = 1;
+       reg_dst(&new_inst.Dst[0], &ctx->tmp[A].dst, TGSI_WRITEMASK_XYZW);
+       new_inst.Instruction.NumSrcRegs = 1;
+       reg_src(&new_inst.Src[0], src, SWIZ(X, Y, Z, W));
+       tctx->emit_instruction(tctx, &new_inst);
+
+       /* ADD dst, src, tmpA */
+       new_inst = tgsi_default_full_instruction();
+       new_inst.Instruction.Opcode = TGSI_OPCODE_ADD;
+       new_inst.Instruction.NumDstRegs = 1;
+       reg_dst(&new_inst.Dst[0], dst, TGSI_WRITEMASK_XYZW);
+       new_inst.Instruction.NumSrcRegs = 2;
+       reg_src(&new_inst.Src[0], src, SWIZ(X, Y, Z, W));
+       reg_src(&new_inst.Src[1], &ctx->tmp[A].src, SWIZ(X, Y, Z, W));
+       tctx->emit_instruction(tctx, &new_inst);
+    }
+}
+
 /* XPD - Cross Product
  *   dst.x = src0.y \times src1.z - src1.y \times src0.z
  *   dst.y = src0.z \times src1.x - src1.z \times src0.x
@@ -1385,6 +1429,11 @@ transform_instr(struct tgsi_transform_context *tctx,
            goto skip;
        transform_flr(tctx, inst);
        break;
+   case TGSI_OPCODE_CEIL:
+       if (!ctx->config->lower_CEIL)
+           goto skip;
+       transform_ceil(tctx, inst);
+       break;
    case TGSI_OPCODE_XPD:
       if (!ctx->config->lower_XPD)
          goto skip;
@@ -1510,6 +1559,7 @@ tgsi_transform_lowering(const struct tgsi_lowering_config *config,
    /* if there are no instructions to lower, then we are done: */
    if (!(OPCS(DST) ||
          OPCS(FLR) ||
+         OPCS(CEIL) ||
          OPCS(XPD) ||
          OPCS(SCS) ||
          OPCS(LRP) ||
@@ -1543,6 +1593,10 @@ tgsi_transform_lowering(const struct tgsi_lowering_config *config,
       newlen += FLR_GROW * OPCS(FLR);
       numtmp = MAX2(numtmp, FLR_TMP);
    }
+   if (OPCS(CEIL)) {
+      newlen += CEIL_GROW * OPCS(CEIL);
+      numtmp = MAX2(numtmp, CEIL_TMP);
+   }
    if (OPCS(XPD)) {
       newlen += XPD_GROW * OPCS(XPD);
       numtmp = MAX2(numtmp, XPD_TMP);
diff --git a/src/gallium/auxiliary/tgsi/tgsi_lowering.h b/src/gallium/auxiliary/tgsi/tgsi_lowering.h
index 803f84e..f2d02a4 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_lowering.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_lowering.h
@@ -56,6 +56,7 @@ struct tgsi_lowering_config
     */
    unsigned lower_DST:1;
    unsigned lower_FLR:1;
+   unsigned lower_CEIL:1;
    unsigned lower_XPD:1;
    unsigned lower_SCS:1;
    unsigned lower_LRP:1;
-- 
2.5.5