[llvm] [UTC][NFC] Indent switch cases (PR #165212)

[Kunqiu Chen via llvm-commits]

https://github.com/Camsyn created https://github.com/llvm/llvm-project/pull/165212

LLVM prints switch cases indented by 2 additional spaces, as follows:
```LLVM
  switch i32 %x, label %default [
    i32 0, label %phi
    i32 1, label %phi
  ]
```

Since this only changes the output IR of update_test_checks.py and does not change the logic of the File Check Pattern, there seems to be no need to update the existing test cases.


>From 144da611f972df24ee0f9378c62e23e2181b8cee Mon Sep 17 00:00:00 2001
From: Camsyn <camsyn at foxmail.com>
Date: Mon, 27 Oct 2025 16:18:09 +0800
Subject: [PATCH] [UTC][NFC] Indent switch cases

---
 llvm/utils/UpdateTestChecks/common.py | 1 +
 llvm/utils/update_test_checks.py      | 9 +++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/llvm/utils/UpdateTestChecks/common.py b/llvm/utils/UpdateTestChecks/common.py
index a5e3c39bfdecd..1ba716112f527 100644
--- a/llvm/utils/UpdateTestChecks/common.py
+++ b/llvm/utils/UpdateTestChecks/common.py
@@ -606,6 +606,7 @@ def invoke_tool(exe, cmd_args, ir, preprocess_cmd=None, verbose=False):
 DEBUG_ONLY_ARG_RE = re.compile(r"-debug-only[= ]([^ ]+)")
 
 IS_DEBUG_RECORD_RE = re.compile(r"^(\s+)#dbg_")
+IS_SWITCH_CASE_RE = re.compile(r"^\s+i\d{1,2} \d+, label %\w+")
 
 SCRUB_LEADING_WHITESPACE_RE = re.compile(r"^(\s+)")
 SCRUB_WHITESPACE_RE = re.compile(r"(?!^(|  \w))[ \t]+", flags=re.M)
diff --git a/llvm/utils/update_test_checks.py b/llvm/utils/update_test_checks.py
index 3b562fbc54f78..37d046e53aa82 100755
--- a/llvm/utils/update_test_checks.py
+++ b/llvm/utils/update_test_checks.py
@@ -260,9 +260,14 @@ def update_test(ti: common.TestInfo):
                 skip_same_checks=dropped_previous_line,
             ):
                 # This input line of the function body will go as-is into the output.
-                # Except make leading whitespace uniform: 2 spaces. 4 for debug records.
+                # Except make leading whitespace uniform: 2 spaces. 4 for debug records/switch cases.
                 indent = (
-                    "  " if not common.IS_DEBUG_RECORD_RE.match(input_line) else "    "
+                    " " * 4
+                    if (
+                        common.IS_DEBUG_RECORD_RE.match(input_line)
+                        or common.IS_SWITCH_CASE_RE.match(input_line)
+                    )
+                    else " " * 2
                 )
                 input_line = common.SCRUB_LEADING_WHITESPACE_RE.sub(indent, input_line)
                 output_lines.append(input_line)