Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(137)

Unified Diff: src/utils.h

Issue 190383002: Handle non-power-of-2 divisors in division-like operations (Closed) Base URL: https://v8.googlecode.com/svn/branches/bleeding_edge
Patch Set: Rebased Created 6 years, 9 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « src/ia32/macro-assembler-ia32.cc ('k') | src/utils.cc » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: src/utils.h
diff --git a/src/utils.h b/src/utils.h
index a20e2092612784368bdeae6b39322203bd30dbc5..753822614cdac7de30fee972523cc2814509628f 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -105,32 +105,6 @@ inline int MostSignificantBit(uint32_t x) {
}
-// Magic numbers for integer division.
-// These are kind of 2's complement reciprocal of the divisors.
-// Details and proofs can be found in:
-// - Hacker's Delight, Henry S. Warren, Jr.
-// - The PowerPC Compiler Writer’s Guide
-// and probably many others.
-// See details in the implementation of the algorithm in
-// lithium-codegen-arm.cc : LCodeGen::TryEmitSignedIntegerDivisionByConstant().
-struct DivMagicNumbers {
- unsigned M;
- unsigned s;
-};
-
-const DivMagicNumbers InvalidDivMagicNumber= {0, 0};
-const DivMagicNumbers DivMagicNumberFor3 = {0x55555556, 0};
-const DivMagicNumbers DivMagicNumberFor5 = {0x66666667, 1};
-const DivMagicNumbers DivMagicNumberFor7 = {0x92492493, 2};
-const DivMagicNumbers DivMagicNumberFor9 = {0x38e38e39, 1};
-const DivMagicNumbers DivMagicNumberFor11 = {0x2e8ba2e9, 1};
-const DivMagicNumbers DivMagicNumberFor25 = {0x51eb851f, 3};
-const DivMagicNumbers DivMagicNumberFor125 = {0x10624dd3, 3};
-const DivMagicNumbers DivMagicNumberFor625 = {0x68db8bad, 8};
-
-const DivMagicNumbers DivMagicNumberFor(int32_t divisor);
-
-
// The C++ standard leaves the semantics of '>>' undefined for
// negative signed operands. Most implementations do the right thing,
// though.
« no previous file with comments | « src/ia32/macro-assembler-ia32.cc ('k') | src/utils.cc » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698