Mercurial > hg > truffle
changeset 70:b683f557224b
6661247: Internal bug in 32-bit HotSpot optimizer while bit manipulations
Summary: copy elimination of a constant value results in incorrect execution
Reviewed-by: kvn, sgoldman, rasbold
| author | never |
|---|---|
| date | Wed, 19 Mar 2008 15:14:36 -0700 |
| parents | 8bb88f9877e5 |
| children | 3d62cb85208d |
| files | src/share/vm/opto/chaitin.hpp src/share/vm/opto/postaloc.cpp test/compiler/6661247/Test.java |
| diffstat | 3 files changed, 164 insertions(+), 7 deletions(-) [+] |
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--- a/src/share/vm/opto/chaitin.hpp Tue Mar 18 23:54:17 2008 -0700 +++ b/src/share/vm/opto/chaitin.hpp Wed Mar 19 15:14:36 2008 -0700 @@ -457,7 +457,8 @@ bool may_be_copy_of_callee( Node *def ) const; // If nreg already contains the same constant as val then eliminate it - bool eliminate_copy_of_constant(Node* val, Block *current_block, Node_List& value, Node_List ®nd, + bool eliminate_copy_of_constant(Node* val, Node* n, + Block *current_block, Node_List& value, Node_List ®nd, OptoReg::Name nreg, OptoReg::Name nreg2); // Extend the node to LRG mapping void add_reference( const Node *node, const Node *old_node);
--- a/src/share/vm/opto/postaloc.cpp Tue Mar 18 23:54:17 2008 -0700 +++ b/src/share/vm/opto/postaloc.cpp Wed Mar 19 15:14:36 2008 -0700 @@ -253,7 +253,8 @@ // nodes can represent the same constant so the type and rule of the // MachNode must be checked to ensure equivalence. // -bool PhaseChaitin::eliminate_copy_of_constant(Node* val, Block *current_block, +bool PhaseChaitin::eliminate_copy_of_constant(Node* val, Node* n, + Block *current_block, Node_List& value, Node_List& regnd, OptoReg::Name nreg, OptoReg::Name nreg2) { if (value[nreg] != val && val->is_Con() && @@ -269,12 +270,12 @@ // Since they are equivalent the second one if redundant and can // be removed. // - // val will be replaced with the old value but val might have + // n will be replaced with the old value but n might have // kills projections associated with it so remove them now so that // yank_if_dead will be able to elminate the copy once the uses // have been transferred to the old[value]. - for (DUIterator_Fast imax, i = val->fast_outs(imax); i < imax; i++) { - Node* use = val->fast_out(i); + for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { + Node* use = n->fast_out(i); if (use->is_Proj() && use->outcnt() == 0) { // Kill projections have no users and one input use->set_req(0, C->top()); @@ -521,7 +522,7 @@ // then 'n' is a useless copy. Do not update the register->node // mapping so 'n' will go dead. if( value[nreg] != val ) { - if (eliminate_copy_of_constant(val, b, value, regnd, nreg, OptoReg::Bad)) { + if (eliminate_copy_of_constant(val, n, b, value, regnd, nreg, OptoReg::Bad)) { n->replace_by(regnd[nreg]); j -= yank_if_dead(n,b,&value,®nd); } else { @@ -549,7 +550,7 @@ nreg_lo = tmp.find_first_elem(); } if( value[nreg] != val || value[nreg_lo] != val ) { - if (eliminate_copy_of_constant(n, b, value, regnd, nreg, nreg_lo)) { + if (eliminate_copy_of_constant(val, n, b, value, regnd, nreg, nreg_lo)) { n->replace_by(regnd[nreg]); j -= yank_if_dead(n,b,&value,®nd); } else {
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/compiler/6661247/Test.java Wed Mar 19 15:14:36 2008 -0700 @@ -0,0 +1,155 @@ +/* + * Copyright 2008 Sun Microsystems, Inc. All rights reserved. + * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + */ + +/* + * @test + * @bug 6661247 + * @summary Internal bug in 32-bit HotSpot optimizer while bit manipulations + */ + +import java.util.Random; +import java.nio.*; + +// This isn't a completely reliable test for 6661247 since the results +// depend on what the local schedule looks like but it does reproduce +// the issue in current builds. + +public class Test { + + public static void test(boolean[] src, int srcPos, LongBuffer dest, long destPos, int count) { + int countStart = (destPos & 63) == 0 ? 0 : 64 - (int)(destPos & 63); + if (countStart > count) + countStart = count; + for (int srcPosMax = srcPos + countStart; srcPos < srcPosMax; srcPos++, destPos++) { + if (src[srcPos]) + dest.put((int)(destPos >>> 6), dest.get((int)(destPos >>> 6)) | 1L << (destPos & 63)); + else + dest.put((int)(destPos >>> 6), dest.get((int)(destPos >>> 6)) & ~(1L << (destPos & 63))); + } + count -= countStart; + int cnt = count >>> 6; + for (int k = (int)(destPos >>> 6), kMax = k + cnt; k < kMax; k++) { + int low = (src[srcPos] ? 1 : 0) + | (src[srcPos + 1] ? 1 << 1 : 0) + | (src[srcPos + 2] ? 1 << 2 : 0) + | (src[srcPos + 3] ? 1 << 3 : 0) + | (src[srcPos + 4] ? 1 << 4 : 0) + | (src[srcPos + 5] ? 1 << 5 : 0) + | (src[srcPos + 6] ? 1 << 6 : 0) + | (src[srcPos + 7] ? 1 << 7 : 0) + | (src[srcPos + 8] ? 1 << 8 : 0) + | (src[srcPos + 9] ? 1 << 9 : 0) + | (src[srcPos + 10] ? 1 << 10 : 0) + | (src[srcPos + 11] ? 1 << 11 : 0) + | (src[srcPos + 12] ? 1 << 12 : 0) + | (src[srcPos + 13] ? 1 << 13 : 0) + | (src[srcPos + 14] ? 1 << 14 : 0) + | (src[srcPos + 15] ? 1 << 15 : 0) + | (src[srcPos + 16] ? 1 << 16 : 0) + | (src[srcPos + 17] ? 1 << 17 : 0) + | (src[srcPos + 18] ? 1 << 18 : 0) + | (src[srcPos + 19] ? 1 << 19 : 0) + | (src[srcPos + 20] ? 1 << 20 : 0) + | (src[srcPos + 21] ? 1 << 21 : 0) + | (src[srcPos + 22] ? 1 << 22 : 0) + | (src[srcPos + 23] ? 1 << 23 : 0) + | (src[srcPos + 24] ? 1 << 24 : 0) + | (src[srcPos + 25] ? 1 << 25 : 0) + | (src[srcPos + 26] ? 1 << 26 : 0) + | (src[srcPos + 27] ? 1 << 27 : 0) + | (src[srcPos + 28] ? 1 << 28 : 0) + | (src[srcPos + 29] ? 1 << 29 : 0) + | (src[srcPos + 30] ? 1 << 30 : 0) + | (src[srcPos + 31] ? 1 << 31 : 0) + ; + srcPos += 32; + int high = (src[srcPos] ? 1 : 0) // PROBLEM! + | (src[srcPos + 1] ? 1 << 1 : 0) + | (src[srcPos + 2] ? 1 << 2 : 0) + | (src[srcPos + 3] ? 1 << 3 : 0) + | (src[srcPos + 4] ? 1 << 4 : 0) + | (src[srcPos + 5] ? 1 << 5 : 0) + | (src[srcPos + 6] ? 1 << 6 : 0) + | (src[srcPos + 7] ? 1 << 7 : 0) + | (src[srcPos + 8] ? 1 << 8 : 0) + | (src[srcPos + 9] ? 1 << 9 : 0) + | (src[srcPos + 10] ? 1 << 10 : 0) + | (src[srcPos + 11] ? 1 << 11 : 0) + | (src[srcPos + 12] ? 1 << 12 : 0) + | (src[srcPos + 13] ? 1 << 13 : 0) + | (src[srcPos + 14] ? 1 << 14 : 0) + | (src[srcPos + 15] ? 1 << 15 : 0) + | (src[srcPos + 16] ? 1 << 16 : 0) + | (src[srcPos + 17] ? 1 << 17 : 0) + | (src[srcPos + 18] ? 1 << 18 : 0) + | (src[srcPos + 19] ? 1 << 19 : 0) + | (src[srcPos + 20] ? 1 << 20 : 0) + | (src[srcPos + 21] ? 1 << 21 : 0) + | (src[srcPos + 22] ? 1 << 22 : 0) + | (src[srcPos + 23] ? 1 << 23 : 0) + | (src[srcPos + 24] ? 1 << 24 : 0) + | (src[srcPos + 25] ? 1 << 25 : 0) + | (src[srcPos + 26] ? 1 << 26 : 0) + | (src[srcPos + 27] ? 1 << 27 : 0) + | (src[srcPos + 28] ? 1 << 28 : 0) + | (src[srcPos + 29] ? 1 << 29 : 0) + | (src[srcPos + 30] ? 1 << 30 : 0) + | (src[srcPos + 31] ? 1 << 31 : 0) + ; + srcPos += 32; + dest.put(k, ((long)low & 0xFFFFFFFFL) | (((long)high) << 32)); + destPos += 64; + } + int countFinish = count & 63; + for (int srcPosMax = srcPos + countFinish; srcPos < srcPosMax; srcPos++, destPos++) { + if (src[srcPos]) + dest.put((int)(destPos >>> 6), dest.get((int)(destPos >>> 6)) | 1L << (destPos & 63)); + else + dest.put((int)(destPos >>> 6), dest.get((int)(destPos >>> 6)) & ~(1L << (destPos & 63))); + } + } + public static void main(String[] args) { + Random r = new Random(); + int entries = 1000; + boolean[] src = new boolean[entries * 64]; + long[] dest = new long[entries]; + long[] result = new long[entries]; + + for (int c = 0; c < 2000; c++) { + for (int i = 0; i < entries; i++) { + long l = r.nextLong(); + for (int bit = 0; bit < 64; bit++) { + src[i * 64 + bit] = (l & (1L << bit)) != 0; + } + dest[i] = 0; + result[i] = l; + } + test(src, 0, LongBuffer.wrap(dest, 0, dest.length), 0, src.length); + for (int i = 0; i < entries; i++) { + if (dest[i] != result[i]) { + throw new InternalError(i + ": " + Long.toHexString(dest[i]) + " != " + Long.toHexString(result[i])); + } + } + } + } +}