[clang] [clang][bytecode] Only count taken jumps as steps (PR #201845)

[Timm Baeder via cfe-commits]

Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/201845 at github.com>


https://github.com/tbaederr updated https://github.com/llvm/llvm-project/pull/201845

>From 2287ef041ebfd2e7089bec98c6a9cfb28213cb73 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Fri, 5 Jun 2026 16:09:32 +0200
Subject: [PATCH 1/2] asdf

---
 clang/lib/AST/ByteCode/Interp.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/clang/lib/AST/ByteCode/Interp.cpp b/clang/lib/AST/ByteCode/Interp.cpp
index 699b034c3c683..f6cac7aeb9fb5 100644
--- a/clang/lib/AST/ByteCode/Interp.cpp
+++ b/clang/lib/AST/ByteCode/Interp.cpp
@@ -65,15 +65,17 @@ static bool Jmp(InterpState &S, CodePtr &PC, int32_t Offset) {
 static bool Jt(InterpState &S, CodePtr &PC, int32_t Offset) {
   if (S.Stk.pop<bool>()) {
     PC += Offset;
+    return S.noteStep(PC);
   }
-  return S.noteStep(PC);
+  return true;
 }
 
 static bool Jf(InterpState &S, CodePtr &PC, int32_t Offset) {
   if (!S.Stk.pop<bool>()) {
     PC += Offset;
+    return S.noteStep(PC);
   }
-  return S.noteStep(PC);
+  return true;
 }
 
 static void diagnoseMissingInitializer(InterpState &S, CodePtr OpPC,

>From e8770c7fa9351f87c015fc117a7db7b74c9a29aa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Mon, 8 Jun 2026 08:35:33 +0200
Subject: [PATCH 2/2] Add test case

---
 clang/test/AST/ByteCode/switch-case-steps.cpp | 120 ++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 clang/test/AST/ByteCode/switch-case-steps.cpp

diff --git a/clang/test/AST/ByteCode/switch-case-steps.cpp b/clang/test/AST/ByteCode/switch-case-steps.cpp
new file mode 100644
index 0000000000000..c3fb10be300bb
--- /dev/null
+++ b/clang/test/AST/ByteCode/switch-case-steps.cpp
@@ -0,0 +1,120 @@
+// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++23 %s -fconstexpr-steps=2000
+// RUN: %clang_cc1                                         -std=c++23 %s -fconstexpr-steps=2000
+
+
+
+constexpr int char_to_int(char ch) {
+  switch (ch) {
+  case '0':
+    return 0;
+  case '1':
+    return 1;
+  case '2':
+    return 2;
+  case '3':
+    return 3;
+  case '4':
+    return 4;
+  case '5':
+    return 5;
+  case '6':
+    return 6;
+  case '7':
+    return 7;
+  case '8':
+    return 8;
+  case '9':
+    return 9;
+  case 'a':
+  case 'A':
+    return 10;
+  case 'b':
+  case 'B':
+    return 11;
+  case 'c':
+  case 'C':
+    return 12;
+  case 'd':
+  case 'D':
+    return 13;
+  case 'e':
+  case 'E':
+    return 14;
+  case 'f':
+  case 'F':
+    return 15;
+  case 'g':
+  case 'G':
+    return 16;
+  case 'h':
+  case 'H':
+    return 17;
+  case 'i':
+  case 'I':
+    return 18;
+  case 'j':
+  case 'J':
+    return 19;
+  case 'k':
+  case 'K':
+    return 20;
+  case 'l':
+  case 'L':
+    return 21;
+  case 'm':
+  case 'M':
+    return 22;
+  case 'n':
+  case 'N':
+    return 23;
+  case 'o':
+  case 'O':
+    return 24;
+  case 'p':
+  case 'P':
+    return 25;
+  case 'q':
+  case 'Q':
+    return 26;
+  case 'r':
+  case 'R':
+    return 27;
+  case 's':
+  case 'S':
+    return 28;
+  case 't':
+  case 'T':
+    return 29;
+  case 'u':
+  case 'U':
+    return 30;
+  case 'v':
+  case 'V':
+    return 31;
+  case 'w':
+  case 'W':
+    return 32;
+  case 'x':
+  case 'X':
+    return 33;
+  case 'y':
+  case 'Y':
+    return 34;
+  case 'z':
+  case 'Z':
+    return 35;
+  default:
+    return 0;
+  }
+}
+
+constexpr bool check() {
+  const char *str = "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\n";
+  unsigned sum = 0;
+  for (const char *p = str; *p != '\0'; ++p) {
+    sum+= char_to_int(*p);
+  }
+
+  return sum != 0;
+}
+static_assert(check());