[Mesa-dev] [PATCH 3/4] r600: use ieee version of rcp

[sroland at vmware.com]

From: Roland Scheidegger <sroland at vmware.com>

r600 used the clamped version for rcp, whereas both evergreen and cayman
used the ieee version. I don't know why that discrepancy exists (it does so
since day 1) but there does not seem to be a valid reason for this, so make
it consistent. This seems now safer than before the previous commit (using
the mystery dx10 clamp).
Note that rsq still uses clamped version (as before even though the table
may have suggested otherwise for evergreen) for r600/eg, but not for cayman.
I just don't feel lucky enough to change this (it should also be noted r600
supports sqrt natively, which is always ieee, therefore might not really see
rsqrt with glsl often presumably).
Compile tested only...
---
 src/gallium/drivers/r600/r600_shader.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
index 6a755bb3fd..628c33787e 100644
--- a/src/gallium/drivers/r600/r600_shader.c
+++ b/src/gallium/drivers/r600/r600_shader.c
@@ -8830,11 +8830,7 @@ static const struct r600_shader_tgsi_instruction r600_shader_tgsi_instruction[]
 	[TGSI_OPCODE_MOV]	= { ALU_OP1_MOV, tgsi_op2},
 	[TGSI_OPCODE_LIT]	= { ALU_OP0_NOP, tgsi_lit},
 
-	/* XXX:
-	 * For state trackers other than OpenGL, we'll want to use
-	 * _RECIP_IEEE instead.
-	 */
-	[TGSI_OPCODE_RCP]	= { ALU_OP1_RECIP_CLAMPED, tgsi_trans_srcx_replicate},
+	[TGSI_OPCODE_RCP]	= { ALU_OP1_RECIP_IEEE, tgsi_trans_srcx_replicate},
 
 	[TGSI_OPCODE_RSQ]	= { ALU_OP0_NOP, tgsi_rsq},
 	[TGSI_OPCODE_EXP]	= { ALU_OP0_NOP, tgsi_exp},
@@ -9034,7 +9030,7 @@ static const struct r600_shader_tgsi_instruction eg_shader_tgsi_instruction[] =
 	[TGSI_OPCODE_MOV]	= { ALU_OP1_MOV, tgsi_op2},
 	[TGSI_OPCODE_LIT]	= { ALU_OP0_NOP, tgsi_lit},
 	[TGSI_OPCODE_RCP]	= { ALU_OP1_RECIP_IEEE, tgsi_trans_srcx_replicate},
-	[TGSI_OPCODE_RSQ]	= { ALU_OP1_RECIPSQRT_IEEE, tgsi_rsq},
+	[TGSI_OPCODE_RSQ]	= { ALU_OP0_NOP, tgsi_rsq},
 	[TGSI_OPCODE_EXP]	= { ALU_OP0_NOP, tgsi_exp},
 	[TGSI_OPCODE_LOG]	= { ALU_OP0_NOP, tgsi_log},
 	[TGSI_OPCODE_MUL]	= { ALU_OP2_MUL_IEEE, tgsi_op2},
-- 
2.12.3