Mesa (master): nvfx: implement fp SSG properly

[Luca Barbieri]

Module: Mesa
Branch: master
Commit: 72648ca51fddb99a4b9724524c46a8c774aba820
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=72648ca51fddb99a4b9724524c46a8c774aba820

Author: Luca Barbieri <luca at luca-barbieri.com>
Date:   Sat Sep  4 04:17:16 2010 +0200

nvfx: implement fp SSG properly

---

 src/gallium/drivers/nvfx/nvfx_fragprog.c |   23 ++++++++++++++++++-----
 1 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/gallium/drivers/nvfx/nvfx_fragprog.c b/src/gallium/drivers/nvfx/nvfx_fragprog.c
index 159db99..32d642d 100644
--- a/src/gallium/drivers/nvfx/nvfx_fragprog.c
+++ b/src/gallium/drivers/nvfx/nvfx_fragprog.c
@@ -757,12 +757,25 @@ nvfx_fragprog_parse_instruction(struct nvfx_context* nvfx, struct nvfx_fpc *fpc,
 		nvfx_fp_emit(fpc, arith(sat, SNE, dst, mask, src[0], src[1], none));
 		break;
 	case TGSI_OPCODE_SSG:
-		tmp = nvfx_src(temp(fpc));
-		tmp2 = nvfx_src(temp(fpc));
-		nvfx_fp_emit(fpc, arith(0, SGT, tmp.reg, mask, src[0], nvfx_src(nvfx_reg(NVFXSR_CONST, 0)), none));
-		nvfx_fp_emit(fpc, arith(0, SLT, tmp.reg, mask, src[0], nvfx_src(nvfx_reg(NVFXSR_CONST, 0)), none));
-		nvfx_fp_emit(fpc, arith(sat, ADD, dst, mask, tmp, neg(tmp2), none));
+	{
+		float minonesv[4] = {-1.0, -1.0, -1.0, -1.0};
+		struct nvfx_src minones = swz(nvfx_src(constant(fpc, -1, minonesv)), X, X, X, X);
+
+		insn = arith(sat, MOV, dst, mask, src[0], none, none);
+		insn.cc_update = 1;
+		nvfx_fp_emit(fpc, insn);
+
+		insn = arith(0, STR, dst, mask, none, none, none);
+		insn.cc_test = NVFX_COND_GT;
+		nvfx_fp_emit(fpc, insn);
+
+		if(!sat) {
+			insn = arith(0, MOV, dst, mask, minones, none, none);
+			insn.cc_test = NVFX_COND_LT;
+			nvfx_fp_emit(fpc, insn);
+		}
 		break;
+	}
 	case TGSI_OPCODE_STR:
 		nvfx_fp_emit(fpc, arith(sat, STR, dst, mask, src[0], src[1], none));
 		break;