nir/algebraic: Only replace an instruction once

Without the break, it was possible that an instruction would match multiple
expressions.  If this happened, you could end up trying to replace it
multiple times and get a segfault.  This makes it so that, after a
successful replacement, it moves on to the next instruction.

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>

diff --git a/src/glsl/nir/nir_algebraic.py b/src/glsl/nir/nir_algebraic.py
index 72703beea8a2eb8693a9bb8393e1d17a17e8aaf4..f9b246dd86529879ae1863ccb856511ffc26b38c 100644 (file)
--- a/src/glsl/nir/nir_algebraic.py
+++ b/src/glsl/nir/nir_algebraic.py
@@ -192,8 +192,10 @@ ${pass_name}_block(nir_block *block, void *void_state)
          for (unsigned i = 0; i < ARRAY_SIZE(${pass_name}_${opcode}_xforms); i++) {
             if (nir_replace_instr(alu, ${pass_name}_${opcode}_xforms[i].search,
                                   ${pass_name}_${opcode}_xforms[i].replace,
-                                  state->mem_ctx))
+                                  state->mem_ctx)) {
                state->progress = true;
+               break;
+            }
          }
          break;
       % endfor