Re-enable toLowerCase/toUpperCase acceleration #2098

dhong44 · 2018-06-06T17:31:39Z

Modify API call so that caseConversionHelper receives
underlying arrays and length of string.

Closes: #1934

Signed-off-by: Daniel Hong daniel.hong@live.com

dhong44 · 2018-06-06T17:32:01Z

@fjeremic Could you please review this

fjeremic · 2018-06-06T23:22:35Z

jcl/src/java.base/share/classes/java/lang/String.java

-				return output;
+			int sLength = lengthInternal();
+
+			if (enableCompression && (null == compressionFlag || coder == LATIN1)) {


We need to refactor this code and avoid the duplicate if. Can we merge with the path below?

fjeremic · 2018-06-06T23:24:14Z

jcl/src/java.base/share/classes/java/lang/String.java

@@ -2720,9 +2720,17 @@ public String toLowerCase(Locale locale) {
 		}

 		if (StrHWAvailable() && language == "en") { //$NON-NLS-1$


Since we are in this area of code can we rename this method here to something more sane and place it in the JitHelpers class with proper documentation? Perhaps supportsIntrinsicCaseConversion or if you can think of a better name I'm fine with that?

fjeremic · 2018-06-06T23:25:57Z

jcl/src/java.base/share/classes/java/lang/String.java

+
+			if (enableCompression && (null == compressionFlag || coder == LATIN1)) {
+				byte[] output = new byte[sLength];
+				if (toLowerHWOptimizedLatin1(value, output, sLength))


Perhaps we can match the new name of the check and rename these accordingly to toLowerIntrinsicLatin1 / toLowerIntrinsicUTF16 (similarly for toUpper).

fjeremic · 2018-06-06T23:27:23Z

jcl/src/java.base/share/classes/java/lang/String.java

+				if (toLowerHWOptimizedLatin1(value, output, sLength))
+						return new String(output, LATIN1);
+			} else {
+				byte[] output = new byte[sLength * 2];


This can be factored out as sLength << coder

fjeremic · 2018-06-06T23:28:06Z

jcl/src/java.base/share/classes/java/lang/String.java

+			} else {
+				byte[] output = new byte[sLength * 2];
+				if (toLowerHWOptimizedUTF16(value, output, sLength * 2))
+						return new String(output, UTF16);


Let's stay consistent with the rest of the codebase and add curly brackets around if blocks.

fjeremic · 2018-06-06T23:28:39Z

jcl/src/java.base/share/classes/java/lang/String.java

-	// DO NOT CHANGE CONTENTS OF THESE METHODS
-	private final boolean toUpperHWOptimized(String input) {
+	// DO NOT CHANGE THE CONTENTS OF THESE METHODS
+	private final static boolean toUpperHWOptimizedLatin1(byte[] value, byte[] output, int length) {


Let's move this guy to JitHelpers as well and fully document it. Similarly with others.

fjeremic · 2018-06-06T23:35:42Z

jcl/src/java.base/share/classes/java/lang/String.java

@@ -4569,6 +4593,21 @@ public String(char[] data, int start, int length) {
 		}
 	}

+	String(char[] data, int length, boolean compressed) {


I don't think there is a need for this constructor to exist. Can we not just reuse the one below with length == 0? These things would typically get inlined and the constant will be propagated thus ending up with the same implementation as you have here.

dhong44 · 2018-06-07T19:43:44Z

Depends on eclipse/omr#2650

dhong44 · 2018-06-07T19:59:40Z

Addressed your changes requested from 3fe5f89 in 5d7021f.

fjeremic · 2018-06-07T20:16:24Z

runtime/compiler/x/codegen/J9TreeEvaluator.cpp

-      case TR::java_lang_String_toLowerHWOptimizedLatin1:
-         return TR::TreeEvaluator::compressedStringToLowerCaseEvaluator(node, cg);
+      case TR::com_ibm_jit_JITHelpers_toUpperIntrinsicUTF16:
+         return TR::TreeEvaluator::UTF16StringToUpperCaseEvaluator(node, cg);


We should probably rename these to toUpperIntrinsicUTF16Evaluator for easier search ability. And of course use the same names on Z if needed.

Would the name inlineToUpper in Z be appropriate or should I change it to something like toUpperIntrinsic?

Let's go with toUpperIntrinsic. By grepping for the Java method we should be able to find all related methods/functions in the VM/JIT as well. This is the intention.

Renamed functions in x and z codegen in 5fd75e8.

fjeremic · 2018-06-07T21:12:15Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+   *     Boolean representing the string's compression
+   *
+   *  \return
+   *     0 if the conversion is unsuccessful, a non zero value otherwise


This is not true. The function returns a register which represents the return value of the Java call. We need to JavaDoc the JIT helpers you added to define what the input parameters represent and what the return value represents. This Doxygen comment needs to be modified.

Added JavaDoc comments to JIT helper methods and fixed doxygen comment in 91004aa

fjeremic · 2018-06-07T21:38:07Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+   TR::Instruction* instruction;
+
+   const int elementSizeMask = (isCompressedString) ? 0x0 : 0x1;    // byte or halfword mask
+   const int sizeOfVector = 16;


We cast this variable to an int8_t a little below. Are we able to avoid the cast by redefining the type at source?

fjeremic · 2018-06-07T21:39:43Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+   const bool is64 = TR::Compiler->target.is64Bit();
+   uintptrj_t headerSize = TR::Compiler->om.contiguousArrayHeaderSizeInBytes();
+
+   TR::RegisterDependencyConditions * regDeps = new (cg->trHeapMemory()) TR::RegisterDependencyConditions(0, 14, cg);


I only count 13 dependencies below. Can we save some space?

fjeremic · 2018-06-07T21:40:06Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+   regDeps->addPostCondition(invalidRangeVector, TR::RealRegister::AssignAny);
+   regDeps->addPostCondition(invalidCondVector, TR::RealRegister::AssignAny);
+
+   if (is64){


Formatting of braces should be consistent with the rest of the codebase.

fjeremic · 2018-06-07T21:49:04Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+   // Check for strings lengths that are too big in 32bit
+   if (!is64)
+      {
+      generateRIInstruction(cg, TR::InstOpCode::TMLH, node, lengthRegister, (uint16_t) 0x8000);


Why do we need a cast here? Also doesn't this check if lengthRegister < 0. I don't think this is possible. Can you explain what this code is supposed to handle?

https://github.com/eclipse/openj9/blob/1ca0ab9841f1a6b17fde82402582249853a1e6e7/runtime/compiler/z/codegen/J9TreeEvaluator.cpp#L409-L417

Here there was some justification for this check. It does seem that this is checking for negative lengths, which would never happen so I don't see the need for this. I think this is dead code and can be removed.

fjeremic · 2018-06-07T21:52:16Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+
+   generateRRInstruction(cg, TR::InstOpCode::LR, node, loadLength, lengthRegister);
+
+   // Check for strings lengths that are too big in 32bit


I don't think the bitness of the JVM matters here. Couldn't the same problem happen on 64-bit?

For the same reasons as stated in the comment at Line 407, it seems this whole code block is unnecessary and can be removed.

fjeremic · 2018-06-07T21:53:44Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+   generateVRSbInstruction(cg, TR::InstOpCode::VLL, node, charBufferVector, loadLength, generateS390MemoryReference(sourceRegister, addressOffset, headerSize, cg));
+
+   // Check for invalid characters, go to fallback individual character conversion implementation
+   if(!isCompressedString)


Consistency in space between if and parenthesis. Similarly elsewhere in the function.

fjeremic · 2018-06-07T21:54:10Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+   generateVRRcInstruction(cg, isToUpper ? TR::InstOpCode::VS : TR::InstOpCode::VA, node, modifiedCaseVector, charBufferVector, charOffsetVector, 0x0, 0x0, elementSizeMask);
+   generateVRReInstruction(cg, TR::InstOpCode::VSEL, node, modifiedCaseVector, modifiedCaseVector, charBufferVector, selectionVector);
+
+   instruction = generateVRSbInstruction(cg, TR::InstOpCode::VSTL, node, modifiedCaseVector, loadLength, generateS390MemoryReference(destRegister, addressOffset, headerSize, cg), 0);


Why do we need to set instruction = here?

fjeremic · 2018-06-07T21:54:53Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+
+   generateVRRdInstruction(cg, TR::InstOpCode::VSTRC, node, selectionVector, charBufferVector, alphaRangeVector, alphaCondVector, 0x4, elementSizeMask);
+   generateVRRcInstruction(cg, isToUpper ? TR::InstOpCode::VS : TR::InstOpCode::VA, node, modifiedCaseVector, charBufferVector, charOffsetVector, 0x0, 0x0, elementSizeMask);
+   instruction = generateVRReInstruction(cg, TR::InstOpCode::VSEL, node, modifiedCaseVector, modifiedCaseVector, charBufferVector, selectionVector);


Why do we need to set instruction = here?

fjeremic · 2018-06-07T21:55:44Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+
+   instruction=generateS390LabelInstruction(cg, TR::InstOpCode::LABEL, node, doneLabel);
+   instruction->setEndInternalControlFlow();
+   instruction->setDependencyConditions(regDeps);


I believe this line can be folded into the generateS390LabelInstruction. There should be an overload accepting register dependencies.

fjeremic · 2018-06-07T21:55:57Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

+   cg->generateDebugCounter(isToUpper? "z13/simd/toUpper/null"  : "z13/simd/toLower/null", 1, TR::DebugCounter::Cheap);
+   generateRRInstruction(cg, TR::InstOpCode::getXORRegOpCode(), node, destRegister, destRegister);
+
+   instruction=generateS390LabelInstruction(cg, TR::InstOpCode::LABEL, node, doneLabel);


Formatting around = needs to be fixed.

dhong44 · 2018-06-08T14:21:05Z

============================================================
; Live regs: GPR=5 FPR=0 VRF=0 GPR64=0 AR=0 {GPR_0210, &GPR_0152, GPR_0147, &GPR_0033, &GPR_0032}
------------------------------
 n107n    (  0)  treetop                                                                              [     0x3ff6b081130] bci=[-1,138,2723] rc=0 vc=394 vn=- li=- udi=- nc=1
 n106n    (  2)    icall  com/ibm/jit/JITHelpers.toUpperIntrinsicUTF16([B[BI)Z[#631  final virtual Method -128] [flags 0x20500 0x0 ] ()  [     0x3ff6b0810e0] bci=[-1,138,2723] rc=2 vc=394 vn=- li=- udi=- nc=4 flg=0x20
 n97n     (  1)      aload  java/lang/String.helpers Lcom/ibm/jit/JITHelpers;[#664  final Static] (obj1) [flags 0xa0307 0x0 ] (X!=0 sharedMemory )  [     0x3ff6b080e10] bci=[-1,126,2723] rc=1 vc=394 vn=- li=- udi=- nc=0 flg=0x4
 n99n     (  1)      l2a (X!=0 unneededConv sharedMemory )                                            [     0x3ff6b080eb0] bci=[-1,130,2723] rc=1 vc=394 vn=- li=- udi=- nc=1 flg=0x404
 n516n    (  1)        lshl (compressionSequence )                                                    [     0x3ff6b089100] bci=[-1,130,2723] rc=1 vc=394 vn=- li=- udi=- nc=2 flg=0x800
 n515n    (  1)          ==>iu2l (in GPR_0210) (X!=0 unneededConv )
 n513n    (  1)          iconst 2                                                                     [     0x3ff6b089010] bci=[-1,130,2723] rc=1 vc=394 vn=- li=- udi=- nc=0
 n94n     (  2)      ==>newarray (in &GPR_0152) (X!=0 sharedMemory )
 n105n    (  1)      ishl (X>=0 cannotOverflow )                                                      [     0x3ff6b081090] bci=[-1,137,2723] rc=1 vc=394 vn=- li=- udi=- nc=2 flg=0x1100
 n453n    (  1)        ==>iushr (in GPR_0147) (X>=0 cannotOverflow )
 n104n    (  1)        iconst 1 (X!=0 X>=0 )                                                          [     0x3ff6b081040] bci=[-1,136,2723] rc=1 vc=394 vn=- li=- udi=- nc=0 flg=0x104
------------------------------
------------------------------
 n107n    (  0)  treetop                                                                              [     0x3ff6b081130] bci=[-1,138,2723] rc=0 vc=394 vn=- li=- udi=- nc=1
 n106n    (  1)    icall  com/ibm/jit/JITHelpers.toUpperIntrinsicUTF16([B[BI)Z[#631  final virtual Method -128] [flags 0x20500 0x0 ] (in GPR_0212) ()  [     0x3ff6b0810e0] bci=[-1,138,2723] rc=1 vc=394 vn=- li=- udi=- nc=4 flg=0x20
 n97n     (  0)      aload  java/lang/String.helpers Lcom/ibm/jit/JITHelpers;[#664  final Static] (obj1) [flags 0xa0307 0x0 ] (X!=0 sharedMemory )  [     0x3ff6b080e10] bci=[-1,126,2723] rc=0 vc=394 vn=- li=- udi=- nc=0 flg=0x4
 n99n     (  0)      l2a (in &GPR_0211) (X!=0 unneededConv sharedMemory )                             [     0x3ff6b080eb0] bci=[-1,130,2723] rc=0 vc=394 vn=- li=- udi=- nc=1 flg=0x404
 n516n    (  0)        lshl (in &GPR_0211) (compressionSequence )                                     [     0x3ff6b089100] bci=[-1,130,2723] rc=0 vc=394 vn=- li=- udi=- nc=2 flg=0x800
 n515n    (  0)          ==>iu2l (in GPR_0210) (X!=0 unneededConv )
 n513n    (  0)          iconst 2                                                                     [     0x3ff6b089010] bci=[-1,130,2723] rc=0 vc=394 vn=- li=- udi=- nc=0
 n94n     (  1)      ==>newarray (in &GPR_0152) (X!=0 sharedMemory )
 n105n    (  0)      ishl (in GPR_0212) (X>=0 cannotOverflow )                                        [     0x3ff6b081090] bci=[-1,137,2723] rc=0 vc=394 vn=- li=- udi=- nc=2 flg=0x1100
 n453n    (  0)        ==>iushr (in GPR_0147) (X>=0 cannotOverflow )
 n104n    (  0)        iconst 1 (X!=0 X>=0 )                                                          [     0x3ff6b081040] bci=[-1,136,2723] rc=0 vc=394 vn=- li=- udi=- nc=0 flg=0x104
------------------------------

 [     0x3ff6b2502c0]	SLLG    &GPR_0211,GPR_0210,2
 [     0x3ff6b250440]	SLLK    GPR_0212,GPR_0147,1
 [     0x3ff6b250c90]	XGR     GPR_0213,GPR_0213	
 [     0x3ff6b250d80]	VGBM    VRF_0219,0x0
 [     0x3ff6b250e80]	VGBM    VRF_0220,0x0
 [     0x3ff6b250f80]	VGBM    VRF_0221,0x0
 [     0x3ff6b251080]	VGBM    VRF_0222,0x0
 [     0x3ff6b251180]	VLEIH   VRF_0219,0x617a,0
 [     0x3ff6b251280]	VLEIH   VRF_0219,0xe0f6,1
 [     0x3ff6b251380]	VLEIH   VRF_0219,0xf8fe,2
 [     0x3ff6b251480]	VUPLHB  VRF_0219,VRF_0219
 [     0x3ff6b251580]	VLEIH   VRF_0220,0xa000,0
 [     0x3ff6b251680]	VLEIH   VRF_0220,0xc000,1
 [     0x3ff6b251780]	VLEIH   VRF_0220,0xa000,2
 [     0x3ff6b251880]	VLEIH   VRF_0220,0xc000,3
 [     0x3ff6b251980]	VLEIH   VRF_0220,0xa000,4
 [     0x3ff6b251a80]	VLEIH   VRF_0220,0xc000,5
 [     0x3ff6b251b80]	VLEIH   VRF_0221,0xdfdf,0
 [     0x3ff6b251c80]	VLEIH   VRF_0221,0xb5b5,1
 [     0x3ff6b251d80]	VLEIH   VRF_0221,0xffff,2
 [     0x3ff6b251e80]	VUPLHB  VRF_0221,VRF_0221
 [     0x3ff6b251f80]	VLEIH   VRF_0222,0x8000,0
 [     0x3ff6b252080]	VLEIH   VRF_0222,0x8000,1
 [     0x3ff6b252180]	VLEIH   VRF_0222,0x8000,2
 [     0x3ff6b252280]	VLEIH   VRF_0222,0x8000,3
 [     0x3ff6b252380]	VLEIH   VRF_0222,0x2000,4
 [     0x3ff6b252480]	VLEIH   VRF_0222,0x2000,5
 [     0x3ff6b252580]	VREPIH  VRF_0218,0x20
 [     0x3ff6b252680]	LR      GPR_0214,GPR_0212	
 [     0x3ff6b252770]	NILF    GPR_0214,15	
 [     0x3ff6b252890]	BRC     VGNOP(0x8), Label L0080		# (Start of internal control flow)
 [     0x3ff6b252990]	SLFI    GPR_0214,1	
 [     0x3ff6b252cb0]	LA      GPR_0223,#672 0(GPR_0213,&GPR_0211)
 [     0x3ff6b252da0]	VLL     VRF_0215,GPR_0214,#673 8(GPR_0223)
 [     0x3ff6b252ea0]	VSTRCHS VRF_0216,VRF_0215,VRF_0221,VRF_0222,1
 [     0x3ff6b252fa0]	BRC     MASK5(0x4), Label L0083	
 [     0x3ff6b2530a0]	VSTRCH  VRF_0216,VRF_0215,VRF_0219,VRF_0220,4
 [     0x3ff6b2531a0]	VSH     VRF_0217,VRF_0215,VRF_0218
 [     0x3ff6b2532a0]	VSEL    VRF_0217,VRF_0217,VRF_0215,VRF_0216
 [     0x3ff6b2535a0]	LA      GPR_0224,#674 0(GPR_0213,&GPR_0152)
 [     0x3ff6b253690]	VSTL    VRF_0217,GPR_0214,#675 8(GPR_0224)
 [     0x3ff6b253790]	AHIK    GPR_0213,GPR_0214,1,	
 [     0x3ff6b2538a0]	Label L0080:	
 [     0x3ff6b2539a0]	CIJ     GPR_0212,Label L0082,16,BM(mask=0x4), 	
 [     0x3ff6b253ab0]	SRL     GPR_0212,GPR_0212,4
 [     0x3ff6b253bb0]	Label L0084:	
 [     0x3ff6b253d70]	VL      VRF_0215,#676 8(GPR_0213,&GPR_0211)
 [     0x3ff6b253e70]	VSTRCHS VRF_0216,VRF_0215,VRF_0221,VRF_0222,1
 [     0x3ff6b253f70]	BRC     MASK5(0x4), Label L0083	
 [     0x3ff6b254070]	VSTRCH  VRF_0216,VRF_0215,VRF_0219,VRF_0220,4
 [     0x3ff6b254170]	VSH     VRF_0217,VRF_0215,VRF_0218
 [     0x3ff6b254270]	VSEL    VRF_0217,VRF_0217,VRF_0215,VRF_0216
 [     0x3ff6b254430]	VST     VRF_0217,#677 8(GPR_0213,&GPR_0152)
 [     0x3ff6b2545f0]	LA      GPR_0213,#678 16(GPR_0213)
 [     0x3ff6b2546e0]	BRCT    GPR_0212,Label L0084	
 [     0x3ff6b2547d0]	Label L0082:	
 [     0x3ff6b2548d0]	LHI     GPR_0212,0x1	
 [     0x3ff6b2549d0]	BRC     NOP(0xf), Label L0081	
 [     0x3ff6b254ad0]	Label L0083:	
 [     0x3ff6b254bd0]	XR      GPR_0212,GPR_0212	
 [     0x3ff6b254f00]	ASSOCREGS
 [     0x3ff6b254cc0]	Label L0081:	
 POST:
 {AssignAny:&GPR_0211:R} {AssignAny:&GPR_0152:R} {AssignAny:GPR_0212:R} {AssignAny:GPR_0213:R} {AssignAny:GPR_0214:R} {AssignAny:VRF_0215:R} {AssignAny:VRF_0216:R} {AssignAny:VRF_0217:R}
 {AssignAny:VRF_0218:R} {AssignAny:VRF_0219:R} {AssignAny:VRF_0220:R} {AssignAny:VRF_0221:R} {AssignAny:VRF_0222:R}	# (End of internal control flow)

============================================================

fjeremic · 2018-06-08T14:37:40Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

-   // The index will begin at 0 and increment in multiples of 16
-   cursor =                  generateRXInstruction          (cg, TR::InstOpCode::getLoadAddressOpCode(), node, rSrcVal, generateS390MemoryReference(rSrcVal, rResidue, 0, cg));                            iComment("source.val += residue");
-   cursor =                  generateRXInstruction          (cg, TR::InstOpCode::getLoadAddressOpCode(), node, rTgtVal, generateS390MemoryReference(rTgtVal, rResidue, 0 ,cg));                            iComment("tgt.val += residue");
+   generateRIEInstruction(cg, is64 ? TR::InstOpCode::CGIJ : TR::InstOpCode::CIJ, node, lengthRegister, sizeOfVector, doneLabel, TR::InstOpCode::COND_BL);


Could we use TR::InstOpCode::getCmpImmBranchRelOpCode() here?

fjeremic · 2018-06-08T14:43:25Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

-   /* ===================== Step 4.0: Setup for core-loop =====================*/
+   // Increment index by the remainder then add 1, since the loadLength contains the highest index, we must go one past that
+   generateRXInstruction(cg, TR::InstOpCode::getLoadAddressOpCode(), node, addressOffset, generateS390MemoryReference(addressOffset, loadLength, 0, cg));
+   generateRILInstruction(cg, is64 ? TR::InstOpCode::ALGFI : TR::InstOpCode::ALFI, node, addressOffset, 1);


Could we introduce a missing TR::InstOpCode helper for this instruction pair?

fjeremic

 [     0x3ff87253590]	LA      GPR_0213,#676 0(GPR_0214,GPR_0213)
 [     0x3ff87253680]	ALGFI   GPR_0213,1

These two instructions can be fused by folding the ALGFI into the memory reference displacement.

 [     0x3ff872548d0]	XGR     &GPR_0152,&GPR_0152

This looks incorrect. Are we using the second child as the return value register? If so that is a bug. Any register you get from an evaluation of a node cannot be clobbered. It must represent the value of the node it was evaluated from at the exit point of any evaluator. You need to allocate a new register for the return value or reuse an existing one. Perhaps can you check if we can use lengthRegister for the return value since we already call gprClobberEvaluate on it?

dhong44 · 2018-06-08T17:16:40Z

~~Depends on eclipse/omr#2656~~

fjeremic · 2018-06-08T17:18:41Z

Depends on eclipse/omr#2656

I don't think we need to depend on this. The ALGFI should go away after previous review is addressed. We should add the helper regardless though.

fjeremic · 2018-06-11T20:21:37Z

jcl/src/java.base/share/classes/com/ibm/jit/JITHelpers.java

@@ -54,9 +54,6 @@ private JITHelpers() {

 	@CallerSensitive
 	public static JITHelpers getHelpers() {
-		if (Reflection.getCallerClass().getClassLoader() != null) {
-			throw new SecurityException("JITHelpers"); //$NON-NLS-1$
-		}


@andrewcraik wanted to point this one out to you. Is this safe? We need a handle to the JITHelpers object in Test_JITHelpers.java so we can do unit testing on the newly added APIs and have full control over expected inputs and outputs to test all corner cases. Unfortunately we cannot get a handle to the object without removing this or going the reflection route which seems a bit dodgy. Are you aware of any reason why this protection was put in place?

I believe this is here for the same reason sun.misc.Unsafe has the same kind of check - to dissuade others from getting the instance easily. Using a trick similar to unsafe to get hold of the instance in the tests would seem better to me than exposing the API in general.

Cool, that makes sense. @dhong44 can you use a similar trick we use in String.java to get a hold of the JITHelpers object and revert the above deleted lines?

DanHeidinga · 2018-06-12T13:25:24Z

jcl/src/java.base/share/classes/java/lang/String.java


 		if (enableCompression && (null == compressionFlag || coder == LATIN1)) {
+
+			if (helpers.supportsIntrinsicCaseConversion() && language == "en") { //$NON-NLS-1$


The interpreter will never execute this code which means it will appear as a cold path due to no interpreter profiling data. Does the intrinsic recognition overcome this?

I believe so. The interpreter will enter the if block immediately above on line 2728 so we will have profiling data for that path. The JIT will fold away the call to helpers.supportsIntrinsicCaseConversion() as a constant at compile time and the flow algorithm in the JIT should propagate the block frequencies to the if at line 2725 to be equal to that of the preceding if.

Just to be cautious though @dhong44 can we collect a log and verify the block frequencies we compute for the block in which we inline the intrinsic? Given your expertise @andrewcraik is my reasoning here valid?

The key question is when the supportsIntrinsicCaseConversion is folded. It looks to be in ilgen so the flow for IProfiling will have a chance to happen - other profilers do not do a flow. The key thing is to check the frequency on the blocks with the custom implementation after cold block marking. I think a log is the best way to verify this is working right.

n1398n BBStart <block_125> (freq 5002) [ 0x3ff4315a4b0] bci=[10,116,2664] rc=0 vc=257 vn=- li=- udi=- nc=0 n1432n treetop [ 0x3ff4315af50] bci=[10,122,2664] rc=0 vc=257 vn=- li=- udi=- nc=1 n1431n newarray jitNewArray[#176 helper Method] [flags 0x400 0x0 ] (skipZeroInit sharedMemory ) [ 0x3ff4315af00] bci=[10,122,2664] rc=2 vc=257 vn=- li=- udi=- nc=2 flg=0x8000 n1429n ishl [ 0x3ff4315ae60] bci=[10,121,2664] rc=1 vc=257 vn=- li=- udi=- nc=2 n1426n iload <auto slot 3>[#796 Auto] [flags 0x3 0x0 ] [ 0x3ff4315ad70] bci=[10,116,2664] rc=1 vc=257 vn=- li=- udi=- nc=0 n1428n iloadi java/lang/String.coder B[#802 final Shadow +8] [flags 0xa0601 0x0 ] [ 0x3ff4315ae10] bci=[10,118,2664] rc=1 vc=257 vn=- li=- udi=- nc=1 n1427n aload <temp slot 3>[#786 Auto] [flags 0x7 0x0 ] (X!=0 sharedMemory ) [ 0x3ff4315adc0] bci=[10,117,2664] rc=1 vc=257 vn=- li=- udi=- nc=0 flg=0x4 n1430n iconst 8 ; array type is byte [ 0x3ff4315aeb0] bci=[10,122,2664] rc=1 vc=257 vn=- li=- udi=- nc=0 n1433n astore <auto slot 4>[#810 Auto] [flags 0x7 0x0 ] [ 0x3ff4315afa0] bci=[10,124,2664] rc=0 vc=257 vn=- li=- udi=- nc=1 n1431n ==>newarray n1438n compressedRefs [ 0x3ff4315b130] bci=[10,130,2666] rc=0 vc=257 vn=- li=- udi=- nc=2 n1436n aloadi java/lang/String.value [B[#804 final Shadow +4] [flags 0x400a0607 0x0 ] [ 0x3ff4315b090] bci=[10,130,2666] rc=2 vc=257 vn=- li=- udi=- nc=1 n1435n aload <temp slot 3>[#786 Auto] [flags 0x7 0x0 ] (X!=0 sharedMemory ) [ 0x3ff4315b040] bci=[10,129,2666] rc=1 vc=257 vn=- li=- udi=- nc=0 flg=0x4 n1437n lconst 0 [ 0x3ff4315b0e0] bci=[10,130,2666] rc=1 vc=257 vn=- li=- udi=- nc=0 n1444n NULLCHK on n1434n [#30] [ 0x3ff4315b310] bci=[10,138,2666] rc=0 vc=257 vn=- li=- udi=- nc=1 n1443n icall com/ibm/jit/JITHelpers.toLowerIntrinsicUTF16([B[BI)Z[#815 final virtual Method -136] [flags 0x20500 0x0 ] () [ 0x3ff4315b2c0] bci=[10,138,2666] rc=3 vc=257 vn=- li=- udi=- nc=4 flg=0x20 n1434n aload java/lang/String.helpers Lcom/ibm/jit/JITHelpers;[#799 final Static] [flags 0xa0307 0x0 ] [ 0x3ff4315aff0] bci=[10,126,2666] rc=1 vc=257 vn=- li=- udi=- nc=0 n1436n ==>aloadi n1439n aload <auto slot 4>[#810 Auto] [flags 0x7 0x0 ] [ 0x3ff4315b180] bci=[10,133,2666] rc=1 vc=257 vn=- li=- udi=- nc=0 n1442n imul [ 0x3ff4315b270] bci=[10,137,2666] rc=1 vc=257 vn=- li=- udi=- nc=2 n1440n iload <auto slot 3>[#796 Auto] [flags 0x3 0x0 ] [ 0x3ff4315b1d0] bci=[10,135,2666] rc=1 vc=257 vn=- li=- udi=- nc=0 n1441n iconst 2 [ 0x3ff4315b220] bci=[10,136,2666] rc=1 vc=257 vn=- li=- udi=- nc=0 n1445n istore <pending push temp 0>[#793 Auto] [flags 0x3 0x800 ] [ 0x3ff4315b360] bci=[10,138,2666] rc=0 vc=257 vn=- li=- udi=- nc=1

Seems to be working as intended. I validated the log with @dhong44. We seem to have good frequencies on the blocks containing the intrinsic calls.

DanHeidinga · 2018-06-12T13:26:44Z

@smlambert @llxia Can one of you review the tests?

fjeremic · 2018-06-12T16:31:43Z

test/functional/Java8andUp/playlist.xml

@@ -1042,7 +1042,7 @@
 	<test>
 		<testCaseName>JCL_Test_JIT_Helper</testCaseName>
 		<command>$(JAVA_COMMAND) $(JVM_OPTIONS) --add-exports=java.base/com.ibm.jit=ALL-UNNAMED \
-	-Xbootclasspath/a:$(Q)$(TEST_RESROOT)$(D)TestResources.jar$(Q) \
+	--add-opens=java.base/com.ibm.jit=ALL-UNNAMED -Xbootclasspath/a:$(Q)$(TEST_RESROOT)$(D)TestResources.jar$(Q) \


While we're in the area can you rename this test case name to "JCL_Test_JITHelpers" to make it searchable since the test file is Test_JITHelpers.java and the class name is JITHelpers. I would like to be able to find this line in the future by grepping for the class name.

This test is only for SE90 and up, SE80 has it's own test above. I don't think the --add-opens is necessary or is even recognized in Java 8.

llxia · 2018-06-13T14:17:46Z

test/functional/Java8andUp/src/org/openj9/test/com/ibm/jit/Test_JITHelpers.java

+		for (int j : edgecaseLengths){
+			buffer = new char[j];
+			if (helpers.toUpperIntrinsicUTF16(Arrays.copyOfRange(lowercaseUTF16Char, 0, j), buffer, j * 2)) {
+				AssertJUnit.assertTrue("UTF16 JITHelper upper case conversion with char arrays of " + j + " letters failed",


Instead of using org.testng.AssertJUnit, we should directly use org.testng.Assert http://static.javadoc.io/org.testng/testng/6.8.17/org/testng/Assert.html
org.testng.AssertJUnit is used when we port/migrate code that uses JUnit's asserts.

llxia · 2018-06-13T19:13:06Z

test/functional/Java8andUp/src/org/openj9/test/java/lang/Test_String.java

@@ -1377,6 +1405,34 @@ public void test_toUpperCase() {

 		AssertJUnit.assertTrue("Wrong conversion", "\u00df".toUpperCase().equals("SS"));

+		// Long strings and strings of lengths near multiples of 16 bytes to test vector HW acceleration edge cases.
+		AssertJUnit.assertTrue("toUpperCase case conversion failed on a long string",


Same here. org.testng.Assert should be used.

dhong44 · 2018-06-13T19:13:51Z

I ran a bumble bench that called toLower on strings of random length between 0 and 1000. With vectorized case conversion the score was about 30 times higher than without.

fjeremic · 2018-06-14T13:45:58Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

-   cursor =                 generateRILInstruction          (cg, TR::InstOpCode::getSubtractLogicalImmOpCode(), node, rResidue, 1);                                                                         iComment("adjust residue for VLL/VSTL (length -> index)");
-
-   /* ===================== Step 3: Residue processing =====================*/
+   generateRRInstruction(cg, TR::InstOpCode::getLoadRegOpCode(), node, loadLength, lengthRegister);


This seems unnecessary given the load above. Can we remove this? Also shouldn't lengthRegister always a 32-bit value? Shouldn't we always use an LR here? Similarly to above, why can't loadLength also be a 32-bit register?

fjeremic · 2018-06-14T13:50:22Z

runtime/compiler/z/codegen/J9TreeEvaluator.cpp

-      cursor =               generateRIInstruction          (cg, TR::InstOpCode::TMLH, node, rLen, (uint16_t) 0x8000);
-      cursor =               generateS390BranchInstruction  (cg, TR::InstOpCode::BRC , TR::InstOpCode::COND_MASK2, node, handleInvalidChars);
-      cursor->setStartInternalControlFlow();
+      generateRRInstruction(cg, TR::InstOpCode::LLGFR, node, lengthRegister, lengthRegister);


Why exactly is this needed? Looking at the instruction selection from #2098 (comment) I see that all uses of this register can be made in a 32-bit context. We seem to be forcing it to be 64-bit here however.

llxia · 2018-06-14T14:26:39Z

test/functional/Java8andUp/src/org/openj9/test/com/ibm/jit/Test_JITHelpers.java

+			}
+        	buffer.getClass();
+		}
+	}


Do we need to test supportsIntrinsicCaseConversion?

I don't think so, since the result of that method when compiled is dependent on the machine. There's no way we could really test that it returns the correct result.

fjeremic · 2018-06-15T17:10:10Z

Jenkins test sanity

fjeremic · 2018-06-18T15:19:55Z

Transferring this to @joransiu as I'll be away for the next two weeks.

Modify API call so that caseConversionHelper recieves underlying arrays and length of string. Closes: eclipse-openj9#1934 Signed-off-by: Daniel Hong <daniel.hong@live.com>

Remove unused String constructors accepting one integer and returning an empty String with an appropriate capacity. Closes: eclipse-openj9#777 Signed-off-by: Daniel Hong <daniel.hong@live.com>

fjeremic added the comp:jit label Jun 6, 2018

fjeremic self-assigned this Jun 6, 2018

fjeremic mentioned this pull request Jun 6, 2018

Update sign-off location instructions #2096

Closed

dhong44 force-pushed the caseConversion branch from afc2c20 to 3fe5f89 Compare June 6, 2018 23:32

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dhong44 force-pushed the caseConversion branch from 23adbd9 to 74ae7db Compare June 14, 2018 18:39

dhong44 changed the title ~~Re-enable toLowerCase/toUpperCase acceleration~~ WIP: Re-enable toLowerCase/toUpperCase acceleration Jun 14, 2018

dhong44 force-pushed the caseConversion branch from 74ae7db to 0d17eb1 Compare June 15, 2018 17:07

fjeremic assigned joransiu and unassigned fjeremic Jun 18, 2018

dhong44 force-pushed the caseConversion branch from 0d17eb1 to 6ff27d0 Compare June 19, 2018 14:17

dhong44 added 2 commits June 27, 2018 16:36

Re-enable toLowerCase/toUpperCase acceleration

b89ef07

Modify API call so that caseConversionHelper recieves underlying arrays and length of string. Closes: eclipse-openj9#1934 Signed-off-by: Daniel Hong <daniel.hong@live.com>

Remove unnecessary String constructors for toUpper/toLower

635a9ad

Remove unused String constructors accepting one integer and returning an empty String with an appropriate capacity. Closes: eclipse-openj9#777 Signed-off-by: Daniel Hong <daniel.hong@live.com>

dhong44 force-pushed the caseConversion branch from 6ff27d0 to 635a9ad Compare June 27, 2018 20:36

fjeremic assigned fjeremic and unassigned joransiu Jul 4, 2018

fjeremic merged commit 15e283c into eclipse-openj9:master Jul 4, 2018

This was referenced Jul 4, 2018

Revert "WIP: Re-enable toLowerCase/toUpperCase acceleration" #2317

Merged

Re-enable toLowerCase/toUpperCase acceleration #2318

Merged

fjeremic changed the title ~~WIP: Re-enable toLowerCase/toUpperCase acceleration~~ Re-enable toLowerCase/toUpperCase acceleration Feb 8, 2019

fjeremic mentioned this pull request Feb 8, 2019

Java 12 functional sanity failure JCL_Test test_toLowerCase_lithuanian #4659

Closed

		@@ -2720,9 +2720,17 @@ public String toLowerCase(Locale locale) {
		}

		if (StrHWAvailable() && language == "en") { //$NON-NLS-1$


		generateRRInstruction(cg, TR::InstOpCode::LR, node, loadLength, lengthRegister);

		// Check for strings lengths that are too big in 32bit


		if (enableCompression && (null == compressionFlag \|\| coder == LATIN1)) {

		if (helpers.supportsIntrinsicCaseConversion() && language == "en") { //$NON-NLS-1$

Re-enable toLowerCase/toUpperCase acceleration #2098

Re-enable toLowerCase/toUpperCase acceleration #2098

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