diff --git a/src/compiler/nir/nir_opt_gcm.c b/src/compiler/nir/nir_opt_gcm.c
index 4546e231f2f..d0cb8f92339 100644
--- a/src/compiler/nir/nir_opt_gcm.c
+++ b/src/compiler/nir/nir_opt_gcm.c
@@ -791,6 +791,20 @@ gcm_place_instr(nir_instr *instr, struct gcm_state *state)
    block_info->last_instr = instr;
 }
 
+/**
+ * Are ALU instructions a and b both contained in the same if/else block?
+ */
+static bool
+weak_gvn(const nir_instr *a, const nir_instr *b)
+{
+   if (a->type != nir_instr_type_alu)
+      return false;
+
+   const struct nir_cf_node *ap = a->block->cf_node.parent;
+   const struct nir_cf_node *bp = b->block->cf_node.parent;
+   return ap && ap == bp && ap->type == nir_cf_node_if;
+}
+
 static bool
 opt_gcm_impl(nir_shader *shader, nir_function_impl *impl, bool value_number)
 {
@@ -820,17 +834,26 @@ opt_gcm_impl(nir_shader *shader, nir_function_impl *impl, bool value_number)
    state.instr_infos =
       rzalloc_array(NULL, struct gcm_instr_info, state.num_instrs);
 
-   if (value_number) {
-      struct set *gvn_set = nir_instr_set_create(NULL);
-      foreach_list_typed_safe(nir_instr, instr, node, &state.instrs) {
-         if (instr->pass_flags & GCM_INSTR_PINNED)
-            continue;
+   /* Perform (at least some) Global Value Numbering (GVN).
+    *
+    * We perform full GVN when `value_number' is true.  This can be too
+    * aggressive, moving values far away and extending their live ranges,
+    * so we don't always want to do it.
+    *
+    * Otherwise, we perform 'weaker' GVN: if identical ALU instructions appear
+    * on both sides of the same if/else block, we allow them to be moved.
+    * This cleans up a lot of mess without being -too- aggressive.
+    */
+   struct set *gvn_set = nir_instr_set_create(NULL);
+   foreach_list_typed_safe(nir_instr, instr, node, &state.instrs) {
+      if (instr->pass_flags & GCM_INSTR_PINNED)
+         continue;
 
-         if (nir_instr_set_add_or_rewrite(gvn_set, instr, NULL))
-            state.progress = true;
-      }
-      nir_instr_set_destroy(gvn_set);
+      if (nir_instr_set_add_or_rewrite(gvn_set, instr,
+                                       value_number ? NULL : weak_gvn))
+         state.progress = true;
    }
+   nir_instr_set_destroy(gvn_set);
 
    foreach_list_typed(nir_instr, instr, node, &state.instrs)
       gcm_schedule_early_instr(instr, &state);