diff options
author | Brian Paul <brian.paul@tungstengraphics.com> | 2008-03-14 13:50:01 -0600 |
---|---|---|
committer | Brian <brian.paul@tungstengraphics.com> | 2008-03-14 13:57:53 -0600 |
commit | e75a204fb9ffa89cf527d7893fe1f1a34427b6dc (patch) | |
tree | 9e0a0e723566af8bfa70a82671631fcd61a2b35e /src/mesa | |
parent | ac06a5c16a989a871777b90b2cd24fc8a93d33e9 (diff) |
mesa: fix emit_clamp() so that we don't use an output register as temporary
IR_CLAMP is decomposed into OPCODE_MIN+OPCODE_MAX. Allocate a temporary
register for the intermediate value so we don't inadvertantly use an output
register (which are write-only on some GPUs).
Diffstat (limited to 'src/mesa')
-rw-r--r-- | src/mesa/shader/slang/slang_emit.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/src/mesa/shader/slang/slang_emit.c b/src/mesa/shader/slang/slang_emit.c index 9947544a085..84c370dc0b9 100644 --- a/src/mesa/shader/slang/slang_emit.c +++ b/src/mesa/shader/slang/slang_emit.c @@ -677,6 +677,7 @@ static struct prog_instruction * emit_clamp(slang_emit_info *emitInfo, slang_ir_node *n) { struct prog_instruction *inst; + slang_ir_node tmpNode; assert(n->Opcode == IR_CLAMP); /* ch[0] = value @@ -722,18 +723,26 @@ emit_clamp(slang_emit_info *emitInfo, slang_ir_node *n) emit(emitInfo, n->Children[1]); emit(emitInfo, n->Children[2]); + /* Some GPUs don't allow reading from output registers. So if the + * dest for this clamp() is an output reg, we can't use that reg for + * the intermediate result. Use a temp register instead. + */ + alloc_temp_storage(emitInfo, &tmpNode, n->Store->Size); + /* tmp = max(ch[0], ch[1]) */ inst = new_instruction(emitInfo, OPCODE_MAX); - storage_to_dst_reg(&inst->DstReg, n->Store, n->Writemask); + storage_to_dst_reg(&inst->DstReg, tmpNode.Store, n->Writemask); storage_to_src_reg(&inst->SrcReg[0], n->Children[0]->Store); storage_to_src_reg(&inst->SrcReg[1], n->Children[1]->Store); - /* tmp = min(tmp, ch[2]) */ + /* n->dest = min(tmp, ch[2]) */ inst = new_instruction(emitInfo, OPCODE_MIN); storage_to_dst_reg(&inst->DstReg, n->Store, n->Writemask); - storage_to_src_reg(&inst->SrcReg[0], n->Store); + storage_to_src_reg(&inst->SrcReg[0], tmpNode.Store); storage_to_src_reg(&inst->SrcReg[1], n->Children[2]->Store); + free_temp_storage(emitInfo->vt, &tmpNode); + return inst; } |