From 168dd9f1470eba9729ba0a3a1bff9caf4ae600d3 Mon Sep 17 00:00:00 2001
From: Cameron Kaiser <classilla@floodgap.com>
Date: Wed, 9 Aug 2017 21:02:02 -0700
Subject: [PATCH] #406: add vmx_haschr and use it

---
 gfx/thebes/gfxFont.cpp           |  8 +++---
 nsprpub/lib/libc/include/plvmx.h |  7 +++++
 nsprpub/lib/libc/src/plvmx.c     | 44 +++++++++++++++++++++++++++++---
 3 files changed, 52 insertions(+), 7 deletions(-)

diff --git a/gfx/thebes/gfxFont.cpp b/gfx/thebes/gfxFont.cpp
index aa75a5d29..05540292a 100644
--- a/gfx/thebes/gfxFont.cpp
+++ b/gfx/thebes/gfxFont.cpp
@@ -2745,7 +2745,7 @@ inline static bool IsChar8Bit(char16_t aCh) { return aCh < 0x100; }
 
 inline static bool HasSpaces(const uint8_t *aString, uint32_t aLen)
 {
-    return VMX_MEMCHR(aString, 0x20, aLen) != nullptr;
+    return VMX_HASCHR(aString, 0x20, aLen);
 }
 
 inline static bool HasSpaces(const char16_t *aString, uint32_t aLen)
@@ -2857,7 +2857,7 @@ gfxFont::SplitAndInitTextRun(gfxContext *aContext,
                                                     aRunScript,
                                                     aVertical,
                                                     aTextRun);
-            if (!ok) {
+            if (MOZ_UNLIKELY(!ok)) {
                 return false;
             }
         } else if (length > 0) {
@@ -2875,7 +2875,7 @@ gfxFont::SplitAndInitTextRun(gfxContext *aContext,
                                               hash, aRunScript, aVertical,
                                               appUnitsPerDevUnit,
                                               wordFlags, tp);
-            if (sw) {
+            if (MOZ_LIKELY(sw)) {
                 aTextRun->CopyGlyphDataFrom(sw, aRunStart + wordStart);
             } else {
                 return false; // failed, presumably out of memory?
@@ -2905,7 +2905,7 @@ gfxFont::SplitAndInitTextRun(gfxContext *aContext,
                                   gfxShapedWord::HashMix(0, boundary),
                                   aRunScript, aVertical, appUnitsPerDevUnit,
                                   flags | gfxTextRunFactory::TEXT_IS_8BIT, tp);
-                if (sw) {
+                if (MOZ_LIKELY(sw)) {
                     aTextRun->CopyGlyphDataFrom(sw, aRunStart + i);
                 } else {
                     return false;
diff --git a/nsprpub/lib/libc/include/plvmx.h b/nsprpub/lib/libc/include/plvmx.h
index 5291e5dee..b4a651c8a 100644
--- a/nsprpub/lib/libc/include/plvmx.h
+++ b/nsprpub/lib/libc/include/plvmx.h
@@ -13,14 +13,21 @@
 extern "C" {
 #endif
 
+int   vmx_haschr(const void *b, int c, size_t len);
 void *vmx_memchr(const void *b, int c, size_t len);
 
 #if defined (__cplusplus)
 }
 #endif
 
+#define VMX_HASCHR vmx_haschr
 #define VMX_MEMCHR vmx_memchr
 #else
+#if defined (__cplusplus)
+#define VMX_HASCHR(a,b,c) (memchr(a,b,c) != nullptr)
+#else
+#define VMX_HASCHR(a,b,c) (!!memchr(a,b,c))
+#endif
 #define VMX_MEMCHR memchr
 #endif
 
diff --git a/nsprpub/lib/libc/src/plvmx.c b/nsprpub/lib/libc/src/plvmx.c
index df1a8ff0b..dd80351b3 100644
--- a/nsprpub/lib/libc/src/plvmx.c
+++ b/nsprpub/lib/libc/src/plvmx.c
@@ -3,12 +3,50 @@
 
 /* VMX/AltiVec specific libc functions for TenFourFox. */
 
-void *vmx_memchr(const void *b, int c, size_t length) {
-
-/* From:
+/* The below is from
 https://github.com/ridiculousfish/HexFiend/blob/4d5bcee5715f5f288649f7471d1da5bd06376f46/framework/sources/HFFastMemchr.m
    with some optimizations and fixes. */
 
+int vmx_haschr(const void *b, int c, size_t length) {
+    const unsigned char *haystack = (const unsigned char *)b;
+    unsigned char needle = (unsigned char)c;
+
+    unsigned prefixLength = (unsigned)((16 - ((unsigned long)haystack) % 16) % 16);
+    unsigned suffixLength = (unsigned)(((unsigned long)(haystack + length)) % 16);
+    // It is possible for altivecLength to be < 0 for short strings.
+    int altivecLength = length - prefixLength - suffixLength;
+
+    if (altivecLength < 16) {
+        while (length--) {
+            if (*haystack == needle) return 1;
+            haystack++;
+        }
+        return 0;
+    }
+
+    size_t numVectors = altivecLength >> 4;
+    while (prefixLength--) {
+        if (*haystack == needle) return 1;
+        haystack++;
+    }
+    
+    unsigned int mashedByte = (needle << 24 ) | (needle << 16) | (needle << 8) | needle;
+    const vector unsigned char searchVector = (vector unsigned int){mashedByte, mashedByte, mashedByte, mashedByte};
+    while (numVectors--) {
+        if (vec_any_eq(*(const vector unsigned char*)haystack, searchVector))
+		return 1;
+        haystack += 16;
+    }
+    
+    while (suffixLength--) {
+        if (*haystack == needle) return 1;
+        haystack++;
+    }
+    
+    return 0;
+}
+
+void *vmx_memchr(const void *b, int c, size_t length) {
     const unsigned char *haystack = (const unsigned char *)b;
     unsigned char needle = (unsigned char)c;