commit 3e02316f71e46ff13cd73ceeccefc77058ff8116
author ysuzuki@apple.com <ysuzuki@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> Fri Jul 30 08:41:25 2021 +0000
committer ysuzuki@apple.com <ysuzuki@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> Fri Jul 30 08:41:25 2021 +0000
tree b6b21f4c2f4981bb3fbcca7ee1a13fd56d1d64fc
parent 2542a03e83a756dac8f6a12689aa9d6ad314d551

[JSC] Use UCPURegister argument to remove zero extension in JIT code
https://bugs.webkit.org/show_bug.cgi?id=228625

Reviewed by Robin Morisset.

Yarr JIT code emits zeroExtend32ToWord for some arguments, but this is not necessary if
argument is defined as UCPURegister. In that case, caller guarantees that top 32bits are
cleared.

* yarr/YarrJIT.cpp:
* yarr/YarrJIT.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@280470 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/JavaScriptCore/ChangeLog

diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
index b9ffeca..b38f3cc 100644
--- a/Source/JavaScriptCore/ChangeLog
+++ b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,17 @@
+2021-07-30  Yusuke Suzuki  <ysuzuki@apple.com>
+
+        [JSC] Use UCPURegister argument to remove zero extension in JIT code
+        https://bugs.webkit.org/show_bug.cgi?id=228625
+
+        Reviewed by Robin Morisset.
+
+        Yarr JIT code emits zeroExtend32ToWord for some arguments, but this is not necessary if
+        argument is defined as UCPURegister. In that case, caller guarantees that top 32bits are
+        cleared.
+
+        * yarr/YarrJIT.cpp:
+        * yarr/YarrJIT.h:
+
 2021-07-29  Myles C. Maxfield  <mmaxfield@apple.com>
 
         Stop building WebGPU and the WHLSL compiler to decrease binary size

Source/JavaScriptCore/yarr/YarrJIT.cpp

diff --git a/Source/JavaScriptCore/yarr/YarrJIT.cpp b/Source/JavaScriptCore/yarr/YarrJIT.cpp
index b1b6d56..fa8868b 100644
--- a/Source/JavaScriptCore/yarr/YarrJIT.cpp
+++ b/Source/JavaScriptCore/yarr/YarrJIT.cpp
@@ -3972,9 +3972,6 @@
             push(X86Registers::r14);
             push(X86Registers::r15);
         }
-        // The ABI doesn't guarantee the upper bits are zero on unsigned arguments, so clear them ourselves.
-        zeroExtend32ToWord(index, index);
-        zeroExtend32ToWord(length, length);
 #if OS(WINDOWS)
         if (m_compileMode == JITCompileMode::IncludeSubpatterns)
             loadPtr(Address(X86Registers::ebp, 6 * sizeof(void*)), output);
@@ -3991,10 +3988,6 @@
             move(TrustedImm32(0xd800), leadingSurrogateTag);
             move(TrustedImm32(0xdc00), trailingSurrogateTag);
         }
-
-        // The ABI doesn't guarantee the upper bits are zero on unsigned arguments, so clear them ourselves.
-        zeroExtend32ToWord(index, index);
-        zeroExtend32ToWord(length, length);
 #elif CPU(ARM_THUMB2)
         push(ARMRegisters::r4);
         push(ARMRegisters::r5);

Source/JavaScriptCore/yarr/YarrJIT.h

diff --git a/Source/JavaScriptCore/yarr/YarrJIT.h b/Source/JavaScriptCore/yarr/YarrJIT.h
index ffc9e32..5929b12 100644
--- a/Source/JavaScriptCore/yarr/YarrJIT.h
+++ b/Source/JavaScriptCore/yarr/YarrJIT.h
@@ -103,7 +103,7 @@
 };
 
 #if CPU(ARM64E)
-extern "C" EncodedMatchResult vmEntryToYarrJIT(const void* input, unsigned start, unsigned length, int* output, MatchingContextHolder* matchingContext, const void* codePtr);
+extern "C" EncodedMatchResult vmEntryToYarrJIT(const void* input, UCPURegister start, UCPURegister length, int* output, MatchingContextHolder* matchingContext, const void* codePtr);
 extern "C" void vmEntryToYarrJITAfter(void);
 #endif
 
@@ -111,10 +111,10 @@
     WTF_MAKE_FAST_ALLOCATED;
     WTF_MAKE_NONCOPYABLE(YarrCodeBlock);
 
-    using YarrJITCode8 = EncodedMatchResult (*)(const LChar* input, unsigned start, unsigned length, int* output, MatchingContextHolder& matchingContext) YARR_CALL;
-    using YarrJITCode16 = EncodedMatchResult (*)(const UChar* input, unsigned start, unsigned length, int* output, MatchingContextHolder& matchingContext) YARR_CALL;
-    using YarrJITCodeMatchOnly8 = EncodedMatchResult (*)(const LChar* input, unsigned start, unsigned length, void*, MatchingContextHolder& matchingContext) YARR_CALL;
-    using YarrJITCodeMatchOnly16 = EncodedMatchResult (*)(const UChar* input, unsigned start, unsigned length, void*, MatchingContextHolder& matchingContext) YARR_CALL;
+    using YarrJITCode8 = EncodedMatchResult (*)(const LChar* input, UCPURegister start, UCPURegister length, int* output, MatchingContextHolder& matchingContext) YARR_CALL;
+    using YarrJITCode16 = EncodedMatchResult (*)(const UChar* input, UCPURegister start, UCPURegister length, int* output, MatchingContextHolder& matchingContext) YARR_CALL;
+    using YarrJITCodeMatchOnly8 = EncodedMatchResult (*)(const LChar* input, UCPURegister start, UCPURegister length, void*, MatchingContextHolder& matchingContext) YARR_CALL;
+    using YarrJITCodeMatchOnly16 = EncodedMatchResult (*)(const UChar* input, UCPURegister start, UCPURegister length, void*, MatchingContextHolder& matchingContext) YARR_CALL;
 
 public:
     YarrCodeBlock() = default;