[compiler-rt] [win/asan] GetInstructionSize: Make `83 EC XX` a generic entry. (PR #119537)

[via llvm-commits]

https://github.com/bernhardu created https://github.com/llvm/llvm-project/pull/119537

This consolidates the two different lines for x86 and x86_64 into a single line for both architectures.
And adds a test line.

CC: @zmodem

>From 1039d4368966df59c25c522309c8f4b21f8df4b1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bernhard=20=C3=9Cbelacker?= <bernhardu at mailbox.org>
Date: Sat, 30 Nov 2024 22:01:06 +0100
Subject: [PATCH] [win/asan] GetInstructionSize: Make `83 EC XX` a generic
 entry.

---
 compiler-rt/lib/interception/interception_win.cpp            | 4 +---
 compiler-rt/lib/interception/tests/interception_win_test.cpp | 1 +
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/compiler-rt/lib/interception/interception_win.cpp b/compiler-rt/lib/interception/interception_win.cpp
index b0fb263b62f156..4afc74933a33bc 100644
--- a/compiler-rt/lib/interception/interception_win.cpp
+++ b/compiler-rt/lib/interception/interception_win.cpp
@@ -634,6 +634,7 @@ static size_t GetInstructionSize(uptr address, size_t* rel_offset = nullptr) {
     case 0xD284:  // 84 D2 : test dl,dl
       return 2;
 
+    case 0xEC83:  // 83 EC XX : sub esp, XX
     case 0xC1F6:  // F6 C1 XX : test cl, XX
       return 3;
 
@@ -644,8 +645,6 @@ static size_t GetInstructionSize(uptr address, size_t* rel_offset = nullptr) {
 
   switch (0x00FFFFFF & *(u32*)address) {
     case 0xF8E483:  // 83 E4 F8 : and esp, 0xFFFFFFF8
-    case 0x64EC83:  // 83 EC 64 : sub esp, 64h
-      return 3;
     case 0x24A48D:  // 8D A4 24 XX XX XX XX : lea esp, [esp + XX XX XX XX]
       return 7;
   }
@@ -873,7 +872,6 @@ static size_t GetInstructionSize(uptr address, size_t* rel_offset = nullptr) {
     case 0x5D8B:  // 8B 5D XX : mov ebx, dword ptr [ebp + XX]
     case 0x7D8B:  // 8B 7D XX : mov edi, dword ptr [ebp + XX]
     case 0x758B:  // 8B 75 XX : mov esi, dword ptr [ebp + XX]
-    case 0xEC83:  // 83 EC XX : sub esp, XX
     case 0x75FF:  // FF 75 XX : push dword ptr [ebp + XX]
       return 3;
     case 0xC1F7:  // F7 C1 XX YY ZZ WW : test ecx, WWZZYYXX
diff --git a/compiler-rt/lib/interception/tests/interception_win_test.cpp b/compiler-rt/lib/interception/tests/interception_win_test.cpp
index 761c07d4288f75..6e01209ac3a7e4 100644
--- a/compiler-rt/lib/interception/tests/interception_win_test.cpp
+++ b/compiler-rt/lib/interception/tests/interception_win_test.cpp
@@ -852,6 +852,7 @@ const struct InstructionSizeData {
     { 2, {0x8B, 0xC1}, 0, "8B C1 : mov eax, ecx"},
     { 2, {0x8B, 0xEC}, 0, "8B EC : mov ebp, esp"},
     { 2, {0x8B, 0xFF}, 0, "8B FF : mov edi, edi"},
+    { 3, {0x83, 0xEC, 0x72}, 0, "83 EC XX : sub esp, XX"},
     { 3, {0xc2, 0x71, 0x72}, 0, "C2 XX XX : ret XX (needed for registering weak functions)"},
     { 5, {0x68, 0x71, 0x72, 0x73, 0x74}, 0, "68 XX XX XX XX : push imm32"},
     { 5, {0xb8, 0x71, 0x72, 0x73, 0x74}, 0, "b8 XX XX XX XX : mov eax, XX XX XX XX"},