[Mesa-dev] [PATCH 1/2] nir: add a helper function for getting the number of source components

Connor Abbott cwabbott0 at gmail.com
Sun Jan 25 08:56:40 PST 2015


Unlike with non-SSA ALU instructions, where if they're per-component
you have to look at the writemask to know which source channels are
being used, SSA ALU instructions always have all the possible channels
enabled so we can just look at the number of components in the SSA
definition for per-component instructions to say how many source
components are being used.

Signed-off-by: Connor Abbott <cwabbott0 at gmail.com>
---
 src/glsl/nir/nir.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
index 0ef83a1..efcaa9d 100644
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -652,6 +652,21 @@ nir_alu_instr_channel_used(nir_alu_instr *instr, unsigned src, unsigned channel)
    return (instr->dest.write_mask >> channel) & 1;
 }
 
+/*
+ * For instructions whose destinations are SSA, get the number of channels
+ * used for a source
+ */
+static inline unsigned
+nir_alu_instr_ssa_src_components(nir_alu_instr *instr, unsigned src)
+{
+   assert(instr->dest.dest.is_ssa);
+
+   if (nir_op_infos[instr->op].input_sizes[src] > 0)
+      return nir_op_infos[instr->op].input_sizes[src];
+
+   return instr->dest.dest.ssa.num_components;
+}
+
 typedef enum {
    nir_deref_type_var,
    nir_deref_type_array,
-- 
2.1.0



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