diff --git a/src/compiler/nir/nir.c b/src/compiler/nir/nir.c
index 9e3fb8e2b78..9dc2c52ee02 100644
--- a/src/compiler/nir/nir.c
+++ b/src/compiler/nir/nir.c
@@ -1946,12 +1946,12 @@ nir_index_instrs(nir_function_impl *impl)
    unsigned index = 0;
 
    nir_foreach_block(block, impl) {
-      block->start_ip = index;
+      block->start_ip = index++;
 
       nir_foreach_instr(instr, block)
          instr->index = index++;
 
-      block->end_ip = index;
+      block->end_ip = index++;
    }
 
    return index;
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 073bfeac82b..3c1965c9a63 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -2627,15 +2627,13 @@ 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.
+    * Value just before the first nir_instr->index in the block, but after
+    * end_ip that of any predecessor block.
     */
    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.
+    * Value just after the last nir_instr->index in the block, but before the
+    * start_ip of any successor block.
     */
    uint32_t end_ip;
 
diff --git a/src/compiler/nir/nir_liveness.c b/src/compiler/nir/nir_liveness.c
index 485066a605e..c748db64420 100644
--- a/src/compiler/nir/nir_liveness.c
+++ b/src/compiler/nir/nir_liveness.c
@@ -382,36 +382,32 @@ nir_live_ssa_defs_per_instr(nir_function_impl *impl)
    for (int i = 0; i < impl->ssa_alloc; i++)
       liveness->defs->start = ~0;
 
-   unsigned last_instr = 0;
    nir_foreach_block(block, impl) {
       unsigned index;
       BITSET_FOREACH_SET(index, block->live_in, impl->ssa_alloc) {
          liveness->defs[index].start = MIN2(liveness->defs[index].start,
-                                            last_instr);
+                                            block->start_ip);
       }
 
       nir_foreach_instr(instr, block) {
          nir_foreach_ssa_def(instr, def_cb, liveness);
-
-         last_instr = instr->index;
       };
 
       /* track an if src's use.  We need to make sure that our value is live
        * across the if reference, where we don't have an instr->index
-       * representing the use.  Mark it as live through the next real
-       * instruction.
+       * representing the use.  Mark it as live through the end of the block.
        */
       nir_if *nif = nir_block_get_following_if(block);
       if (nif) {
          if (nif->condition.is_ssa) {
             liveness->defs[nif->condition.ssa->index].end = MAX2(
-               liveness->defs[nif->condition.ssa->index].end,
-               last_instr + 1);
+               liveness->defs[nif->condition.ssa->index].end, block->end_ip);
          }
       }
 
       BITSET_FOREACH_SET(index, block->live_out, impl->ssa_alloc) {
-         liveness->defs[index].end = MAX2(liveness->defs[index].end, last_instr);
+         liveness->defs[index].end = MAX2(liveness->defs[index].end,
+                                          block->end_ip);
       }
    }
 
diff --git a/src/gallium/auxiliary/nir/nir_to_tgsi.c b/src/gallium/auxiliary/nir/nir_to_tgsi.c
index afea0feaecf..fc82e11ce2e 100644
--- a/src/gallium/auxiliary/nir/nir_to_tgsi.c
+++ b/src/gallium/auxiliary/nir/nir_to_tgsi.c
@@ -48,6 +48,9 @@ struct ntt_compile {
 
    unsigned loop_label;
 
+   /* if condition set up at the end of a block, for ntt_emit_if(). */
+   struct ureg_src if_cond;
+
    /* TGSI temps for our NIR SSA and register values. */
    struct ureg_dst *reg_temp;
    struct ureg_dst *ssa_temp;
@@ -2046,7 +2049,7 @@ static void
 ntt_emit_if(struct ntt_compile *c, nir_if *if_stmt)
 {
    unsigned label;
-   ureg_UIF(c->ureg, ntt_get_src(c, if_stmt->condition), &label);
+   ureg_UIF(c->ureg, c->if_cond, &label);
    ntt_emit_cf_list(c, &if_stmt->then_list);
 
    if (!exec_list_is_empty(&if_stmt->else_list)) {
@@ -2116,6 +2119,15 @@ ntt_emit_block(struct ntt_compile *c, nir_block *block)
       nir_foreach_src(instr, ntt_src_live_interval_end_cb, c);
    }
 
+   /* Set up the if condition for ntt_emit_if(), which we have to do before
+    * freeing up the temps (the "if" is treated as inside the block for liveness
+    * purposes, despite not being an instruction)
+    */
+   nir_if *nif = nir_block_get_following_if(block);
+   if (nif)
+      c->if_cond = ntt_get_src(c, nif->condition);
+
+   /* Free up any SSA temps that are unused at the end of the block. */
    unsigned index;
    BITSET_FOREACH_SET(index, block->live_out, BITSET_WORDS(c->impl->ssa_alloc)) {
       unsigned def_end_ip = c->liveness->defs[index].end;