Remove superfluous checks

Spotted by @regehr, thank you!
WojciechMula · Apr 18, 2018 · 3cdf4d7 · 3cdf4d7
1 parent ecb495f
commit 3cdf4d7
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Showing 5 changed files with 5 additions and 25 deletions.
diff --git a/is_sorted/avx2.cpp b/is_sorted/avx2.cpp
@@ -2,10 +2,6 @@
 
 bool is_sorted_avx2(int32_t* a, size_t n) {
 
-    if (n < 2) {
-        return true;
-    }
-
     const __m256i shuffle_pattern = _mm256_setr_epi32(1, 2, 3, 4, 5, 6, 7, 7);
 
     size_t i = 0;
@@ -27,7 +23,7 @@ bool is_sorted_avx2(int32_t* a, size_t n) {
         i += 7;
     }
 
-    for (/**/; i < n - 1; i++) {
+    for (/**/; i + 1 < n; i++) {
         if (a[i] > a[i + 1])
             return false;
     }

diff --git a/is_sorted/avx2.simd-generic.cpp b/is_sorted/avx2.simd-generic.cpp
@@ -2,10 +2,6 @@
 
 bool is_sorted_avx2_generic(int32_t* a, size_t n) {
 
-    if (n < 2) {
-        return true;
-    }
-
     size_t i = 0;
     if (n > 8) {
         for (/**/; i < n - 8; i += 8) {
@@ -19,7 +15,7 @@ bool is_sorted_avx2_generic(int32_t* a, size_t n) {
         }
     }
 
-    for (/**/; i < n - 1; i++) {
+    for (/**/; i + 1 < n; i++) {
         if (a[i] > a[i + 1])
             return false;
     }

diff --git a/is_sorted/scalar.cpp b/is_sorted/scalar.cpp
@@ -1,9 +1,5 @@
 bool is_sorted(const int32_t* input, size_t n) {
-    if (n < 2) {
-        return true;
-    }
-
-    for (size_t i=0; i < n - 1; i++) {
+    for (size_t i=0; i + 1 < n; i++) {
         if (input[i] > input[i + 1])
             return false;
     }

diff --git a/is_sorted/sse.cpp b/is_sorted/sse.cpp
@@ -2,10 +2,6 @@
 
 bool is_sorted_sse(int32_t* a, size_t n) {
 
-    if (n < 2) {
-        return true;
-    }
-
     size_t i = 0;
     if (n >= 8) {
         __m128i chunk0 = _mm_loadu_si128(reinterpret_cast<const __m128i*>(a));
@@ -24,7 +20,7 @@ bool is_sorted_sse(int32_t* a, size_t n) {
         } while (i < n - 4);
     }
 
-    for (/**/; i < n - 1; i++) {
+    for (/**/; i + 1 < n; i++) {
         if (a[i] > a[i + 1])
             return false;
     }

diff --git a/is_sorted/sse.simd-generic.cpp b/is_sorted/sse.simd-generic.cpp
@@ -2,10 +2,6 @@
 
 bool is_sorted_sse_generic(int32_t* a, size_t n) {
 
-    if (n < 2) {
-        return true;
-    }
-
     size_t i = 0;
     if (n > 4) {
         for (/**/; i < n - 4; i += 4) {
@@ -19,7 +15,7 @@ bool is_sorted_sse_generic(int32_t* a, size_t n) {
         }
     }
 
-    for (/**/; i < n - 1; i++) {
+    for (/**/; i + 1 < n; i++) {
         if (a[i] > a[i + 1])
             return false;
     }