diff --git a/src/compiler/nir/nir.c b/src/compiler/nir/nir.c
index b3a5384f663..66bfb399225 100644
--- a/src/compiler/nir/nir.c
+++ b/src/compiler/nir/nir.c
@@ -1929,8 +1929,12 @@ nir_index_instrs(nir_function_impl *impl)
    unsigned index = 0;
 
    nir_foreach_block(block, impl) {
+      block->start_ip = index;
+
       nir_foreach_instr(instr, block)
          instr->index = index++;
+
+      block->end_ip = index;
    }
 
    return index;
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 70eed7948ea..250d47f79b4 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -747,7 +747,7 @@ typedef struct nir_instr {
    uint8_t pass_flags;
 
    /** generic instruction index. */
-   unsigned index;
+   uint32_t index;
 } nir_instr;
 
 static inline nir_instr *
@@ -2670,6 +2670,19 @@ typedef struct nir_block {
     */
    uint32_t dom_pre_index, dom_post_index;
 
+   /**
+    * nir_instr->index for the first nir_instr in the block.  If the block is
+    * empty, it will be the index of the immediately previous instr, or 0.
+    * Valid when the impl has nir_metadata_instr_index.
+    */
+   uint32_t start_ip;
+   /**
+    * nir_instr->index for the last nir_instr in the block.  If the block is
+    * empty, it will be the same as start_ip.  Valid when the impl has
+    * nir_metadata_instr_index.
+    */
+   uint32_t end_ip;
+
    /* SSA def live in and out for this block; used for liveness analysis.
     * Indexed by ssa_def->index
     */