James Molloy e03e2fa99d [Thumb] Teach ISel how to lower compares of AND bitmasks efficiently ... This recommits r281323, which was backed out for two reasons. One, a selfhost failure, and two, it apparently caused Chromium failures. Actually, the latter was a red herring. The log has expired from the former, but I suspect that was a red herring too (actually caused by another problematic patch of mine). Therefore reapplying, and will watch the bots like a hawk. For the common pattern (CMPZ (AND x, #bitmask), #0), we can do some more efficient instruction selection if the bitmask is one consecutive sequence of set bits (32 - clz(bm) - ctz(bm) == popcount(bm)). 1) If the bitmask touches the LSB, then we can remove all the upper bits and set the flags by doing one LSLS. 2) If the bitmask touches the MSB, then we can remove all the lower bits and set the flags with one LSRS. 3) If the bitmask has popcount == 1 (only one set bit), we can shift that bit into the sign bit with one LSLS and change the condition query from NE/EQ to MI/PL (we could also implement this by shifting into the carry bit and branching on BCC/BCS). 4) Otherwise, we can emit a sequence of LSLS+LSRS to remove the upper and lower zero bits of the mask. 1-3 require only one 16-bit instruction and can elide the CMP. 4 requires two 16-bit instructions but can elide the CMP and doesn't require materializing a complex immediate, so is also a win. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285893 91177308-0d34-0410-b5e6-96231b3b80d8		2016-11-03 10:18:20 +00:00
..
2009-07-17-CrossRegClassCopy.ll
2009-07-21-ISelBug.ll	[ARM] Generate consistent frame records for Thumb2	2016-08-23 09:19:22 +00:00
2009-07-23-CPIslandBug.ll
2009-07-30-PEICrash.ll
2009-08-01-WrongLDRBOpc.ll
2009-08-02-CoalescerBug.ll
2009-08-04-CoalescerAssert.ll
2009-08-04-CoalescerBug.ll
2009-08-04-ScavengerAssert.ll
2009-08-04-SubregLoweringBug2.ll
2009-08-04-SubregLoweringBug3.ll
2009-08-04-SubregLoweringBug.ll	Revert "Change memcpy/memset/memmove to have dest and source alignments."	2015-11-19 05:56:52 +00:00
2009-08-06-SpDecBug.ll
2009-08-07-CoalescerBug.ll
2009-08-07-NeonFPBug.ll
2009-08-08-ScavengerAssert.ll
2009-08-10-ISelBug.ll
2009-08-21-PostRAKill4.ll
2009-09-01-PostRAProlog.ll	Fix an old memset signature in 2009-09-01-PostRAProlog.ll test causing a buildbot failure	2016-06-23 16:07:10 +00:00
2009-09-28-ITBlockBug.ll
2009-10-15-ITBlockBranch.ll
2009-11-01-CopyReg2RegBug.ll
2009-11-11-ScavengerAssert.ll
2009-11-13-STRDBug.ll
2009-12-01-LoopIVUsers.ll	[SCEV] Try to reuse existing value during SCEV expansion	2016-02-04 01:27:38 +00:00
2010-01-06-TailDuplicateLabels.ll
2010-01-19-RemovePredicates.ll
2010-02-11-phi-cycle.ll	ARM: stop emitting blx instructions for most calls on MachO.	2016-05-10 19:17:47 +00:00
2010-02-24-BigStack.ll
2010-03-08-addi12-ccout.ll
2010-03-15-AsmCCClobber.ll	ARM: stop emitting blx instructions for most calls on MachO.	2016-05-10 19:17:47 +00:00
2010-04-15-DynAllocBug.ll
2010-04-26-CopyRegCrash.ll
2010-05-24-rsbs.ll
2010-06-14-NEONCoalescer.ll
2010-06-19-ITBlockCrash.ll
2010-06-21-TailMergeBug.ll
2010-08-10-VarSizedAllocaBug.ll
2010-11-22-EpilogueBug.ll	[ARM] Generate consistent frame records for Thumb2	2016-08-23 09:19:22 +00:00
2010-12-03-AddSPNarrowing.ll
2011-04-21-FILoweringBug.ll
2011-06-07-TwoAddrEarlyClobber.ll
2011-12-16-T2SizeReduceAssert.ll
2012-01-13-CBNZBug.ll	Revert "Change memcpy/memset/memmove to have dest and source alignments."	2015-11-19 05:56:52 +00:00
2013-02-19-tail-call-register-hint.ll
2013-03-02-vduplane-nonconstant-source-index.ll
2013-03-06-vector-sext-operand-scalarize.ll
aapcs.ll
aligned-constants.ll	[MC] Use .p2align instead of .align	2016-01-26 00:03:25 +00:00
aligned-spill.ll	[ARM] Generate consistent frame records for Thumb2	2016-08-23 09:19:22 +00:00
bfi.ll
bfx.ll
bicbfi.ll	[Thumb] Reapply r272251 with a fix for PR28348 (mk 2)	2016-07-05 12:37:13 +00:00
buildvector-crash.ll
carry.ll	Address buildbot fallout from r259065	2016-01-28 18:59:04 +00:00
cbnz.ll
constant-islands-jump-table.ll
constant-islands-new-island-padding.ll
constant-islands-new-island.ll
constant-islands.ll
cortex-fp.ll
crash.ll
cross-rc-coalescing-1.ll
cross-rc-coalescing-2.ll
div.ll
emit-unwinding.ll	ARM: use r7 as the frame-pointer on all MachO targets.	2016-04-11 22:27:40 +00:00
float-cmp.ll
float-intrinsics-double.ll	CodeGen: ensure that libcalls are always AAPCS CC	2016-09-07 17:56:09 +00:00
float-intrinsics-float.ll	CodeGen: ensure that libcalls are always AAPCS CC	2016-09-07 17:56:09 +00:00
float-ops.ll	[Thumb] Teach ISel how to lower compares of AND bitmasks efficiently	2016-11-03 10:18:20 +00:00
frame-pointer.ll	Re-land "[Thumb] Save/restore high registers in Thumb1 pro/epilogues"	2016-10-11 21:14:03 +00:00
frameless2.ll
frameless.ll
ifcvt-compare.ll
ifcvt-neon.ll
ifcvt-rescan-bug-2016-08-22.ll	IfConversion: Rescan diamonds.	2016-08-24 21:34:24 +00:00
ifcvt-rescan-diamonds.ll	IfConversion: Fix bug introduced by rescanning diamonds.	2016-09-02 18:29:26 +00:00
inflate-regs.ll
inlineasm.ll
large-call.ll
large-stack.ll
ldr-str-imm12.ll	[Codegen] Decrease minimum jump table density.	2016-03-29 00:23:41 +00:00
lit.local.cfg
longMACt.ll
lsr-deficiency.ll	[Thumb] Select (CMPZ X, -C) -> (CMPZ (ADDS X, C), 0)	2016-09-09 12:52:24 +00:00
machine-licm.ll
mul_const.ll
pic-load.ll
segmented-stacks.ll
setjmp_longjmp.ll
stack_guard_remat.ll
tail-call-r9.ll
thumb2-adc.ll
thumb2-add2.ll
thumb2-add3.ll
thumb2-add4.ll
thumb2-add5.ll
thumb2-add6.ll
thumb2-add.ll
thumb2-and2.ll
thumb2-and.ll
thumb2-asr2.ll
thumb2-asr.ll
thumb2-bcc.ll
thumb2-bfc.ll
thumb2-bic.ll
thumb2-branch.ll
thumb2-call-tc.ll
thumb2-call.ll	ARM: stop emitting blx instructions for most calls on MachO.	2016-05-10 19:17:47 +00:00
thumb2-cbnz.ll	Codegen: Fix broken assumption in Tail Merge.	2016-06-24 18:16:36 +00:00
thumb2-clz.ll
thumb2-cmn2.ll	[Thumb] Select (CMPZ X, -C) -> (CMPZ (ADDS X, C), 0)	2016-09-09 12:52:24 +00:00
thumb2-cmn.ll
thumb2-cmp2.ll
thumb2-cmp.ll
thumb2-cpsr-liveness.ll	Fix PR26655: Bail out if all regs of an inst BUNDLE have the correct kill flag	2016-05-10 17:57:27 +00:00
thumb2-eor2.ll
thumb2-eor.ll
thumb2-ifcvt1-tc.ll
thumb2-ifcvt1.ll	CodeGen: If Convert blocks that would form a diamond when tail-merged.	2016-08-24 21:34:27 +00:00
thumb2-ifcvt2.ll
thumb2-ifcvt3.ll
thumb2-jtb.ll	[Thumb-1] Synthesize TBB/TBH instructions to make use of compressed jump tables	2016-11-01 13:37:41 +00:00
thumb2-ldm.ll	[ARM] Generate consistent frame records for Thumb2	2016-08-23 09:19:22 +00:00
thumb2-ldr_ext.ll
thumb2-ldr_post.ll
thumb2-ldr_pre.ll
thumb2-ldr.ll
thumb2-ldrb.ll
thumb2-ldrd.ll
thumb2-ldrh.ll
thumb2-lsl2.ll
thumb2-lsl.ll
thumb2-lsr2.ll
thumb2-lsr3.ll
thumb2-lsr.ll
thumb2-mla.ll
thumb2-mls.ll
thumb2-mov.ll
thumb2-mul.ll
thumb2-mulhi.ll
thumb2-mvn2.ll
thumb2-mvn.ll
thumb2-neg.ll
thumb2-orn2.ll
thumb2-orn.ll
thumb2-orr2.ll
thumb2-orr.ll
thumb2-pack.ll
thumb2-rev16.ll
thumb2-rev.ll
thumb2-ror.ll
thumb2-rsb2.ll
thumb2-rsb.ll
thumb2-sbc.ll
thumb2-select_xform.ll
thumb2-select.ll
thumb2-shifter.ll
thumb2-smla.ll
thumb2-smul.ll
thumb2-spill-q.ll
thumb2-str_post.ll
thumb2-str_pre.ll
thumb2-str.ll
thumb2-strb.ll
thumb2-strh.ll
thumb2-sub2.ll
thumb2-sub3.ll
thumb2-sub4.ll
thumb2-sub5.ll
thumb2-sub.ll
thumb2-sxt_rot.ll	[ARM] Improve sxta{b|h} and uxta{b|h} tests	2016-08-10 09:34:34 +00:00
thumb2-sxt-uxt.ll	[ARM] Improve sxta{b|h} and uxta{b|h} tests	2016-08-10 09:34:34 +00:00
thumb2-tbb.ll	[Thumb-1] Synthesize TBB/TBH instructions to make use of compressed jump tables	2016-11-01 13:37:41 +00:00
thumb2-tbh.ll	[Thumb-1] Synthesize TBB/TBH instructions to make use of compressed jump tables	2016-11-01 13:37:41 +00:00
thumb2-teq2.ll
thumb2-teq.ll
thumb2-tst2.ll
thumb2-tst.ll
thumb2-uxt_rot.ll	[ARM] Improve sxta{b|h} and uxta{b|h} tests	2016-08-10 09:34:34 +00:00
thumb2-uxtb.ll
tls1.ll
tls2.ll	Don't print (PLT) on arm.	2016-06-16 16:09:53 +00:00
tpsoft.ll
v8_IT_1.ll
v8_IT_2.ll
v8_IT_3.ll
v8_IT_4.ll
v8_IT_5.ll	Codegen: Fix broken assumption in Tail Merge.	2016-06-24 18:16:36 +00:00
v8_IT_6.ll