[llvm-commits] [llvm] r128845 - in /llvm/trunk: lib/CodeGen/LiveIntervalAnalysis.cpp lib/CodeGen/RegAllocLinearScan.cpp lib/CodeGen/SimpleRegisterCoalescing.cpp test/CodeGen/X86/2008-08-05-SpillerBug.ll test/CodeGen/X86/mcinst-lowering-cmp0.ll
Jakob Stoklund Olesen
stoklund at 2pi.dk
Mon Apr 4 14:00:03 PDT 2011
Author: stoklund
Date: Mon Apr 4 16:00:03 2011
New Revision: 128845
URL: http://llvm.org/viewvc/llvm-project?rev=128845&view=rev
Log:
Allow coalescing with reserved physregs in certain cases:
When a virtual register has a single value that is defined as a copy of a
reserved register, permit that copy to be joined. These virtual register are
usually copies of the stack pointer:
%vreg75<def> = COPY %ESP; GR32:%vreg75
MOV32mr %vreg75, 1, %noreg, 0, %noreg, %vreg74<kill>
MOV32mi %vreg75, 1, %noreg, 8, %noreg, 0
MOV32mi %vreg75<kill>, 1, %noreg, 4, %noreg, 0
CALLpcrel32 ...
Coalescing these virtual registers early decreases register pressure.
Previously, they were coalesced by RALinScan::attemptTrivialCoalescing after
register allocation was completed.
The lower register pressure causes the mcinst-lowering-cmp0.ll test case to fail
because it depends on linear scan spilling a particular register.
I am deleting 2008-08-05-SpillerBug.ll because it is counting the number of
instructions emitted, and its revision history shows the 'correct' count being
edited many times.
Removed:
llvm/trunk/test/CodeGen/X86/2008-08-05-SpillerBug.ll
llvm/trunk/test/CodeGen/X86/mcinst-lowering-cmp0.ll
Modified:
llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp
llvm/trunk/lib/CodeGen/RegAllocLinearScan.cpp
llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
Modified: llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp?rev=128845&r1=128844&r2=128845&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveIntervalAnalysis.cpp Mon Apr 4 16:00:03 2011
@@ -572,7 +572,7 @@
if (TargetRegisterInfo::isVirtualRegister(MO.getReg()))
handleVirtualRegisterDef(MBB, MI, MIIdx, MO, MOIdx,
getOrCreateInterval(MO.getReg()));
- else if (allocatableRegs_[MO.getReg()]) {
+ else {
MachineInstr *CopyMI = NULL;
if (MI->isCopyLike())
CopyMI = MI;
Modified: llvm/trunk/lib/CodeGen/RegAllocLinearScan.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocLinearScan.cpp?rev=128845&r1=128844&r2=128845&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegAllocLinearScan.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegAllocLinearScan.cpp Mon Apr 4 16:00:03 2011
@@ -572,7 +572,7 @@
for (LiveIntervals::iterator i = li_->begin(), e = li_->end(); i != e; ++i) {
if (TargetRegisterInfo::isPhysicalRegister(i->second->reg)) {
- if (!i->second->empty()) {
+ if (!i->second->empty() && allocatableRegs_.test(i->second->reg)) {
mri_->setPhysRegUsed(i->second->reg);
fixed_.push_back(std::make_pair(i->second, i->second->begin()));
}
Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp?rev=128845&r1=128844&r2=128845&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp Mon Apr 4 16:00:03 2011
@@ -919,13 +919,23 @@
/// are not spillable! If the destination interval uses are far away, think
/// twice about coalescing them!
bool SimpleRegisterCoalescing::shouldJoinPhys(CoalescerPair &CP) {
+ bool Allocatable = li_->isAllocatable(CP.getDstReg());
+ LiveInterval &JoinVInt = li_->getInterval(CP.getSrcReg());
+
+ /// Always join simple intervals that are defined by a single copy from a
+ /// reserved register. This doesn't increase register pressure, so it is
+ /// always beneficial.
+ if (!Allocatable && CP.isFlipped() && JoinVInt.containsOneValue())
+ return true;
+
if (DisablePhysicalJoin) {
DEBUG(dbgs() << "\tPhysreg joins disabled.\n");
return false;
}
- // Only coalesce to allocatable physreg.
- if (!li_->isAllocatable(CP.getDstReg())) {
+ // Only coalesce to allocatable physreg, we don't want to risk modifying
+ // reserved registers.
+ if (!Allocatable) {
DEBUG(dbgs() << "\tRegister is an unallocatable physreg.\n");
return false; // Not coalescable.
}
@@ -944,8 +954,6 @@
// FIXME: Why are we skipping this test for partial copies?
// CodeGen/X86/phys_subreg_coalesce-3.ll needs it.
if (!CP.isPartial()) {
- LiveInterval &JoinVInt = li_->getInterval(CP.getSrcReg());
-
const TargetRegisterClass *RC = mri_->getRegClass(CP.getSrcReg());
unsigned Threshold = allocatableRCRegs_[RC].count() * 2;
unsigned Length = li_->getApproximateInstructionCount(JoinVInt);
Removed: llvm/trunk/test/CodeGen/X86/2008-08-05-SpillerBug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2008-08-05-SpillerBug.ll?rev=128844&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/2008-08-05-SpillerBug.ll (original)
+++ llvm/trunk/test/CodeGen/X86/2008-08-05-SpillerBug.ll (removed)
@@ -1,44 +0,0 @@
-; RUN: llc < %s -mtriple=i386-apple-darwin -mcpu=yonah -pre-RA-sched=list-burr -disable-fp-elim -stats |& grep asm-printer | grep 55
-; PR2568
-
- at g_3 = external global i16 ; <i16*> [#uses=1]
- at g_5 = external global i32 ; <i32*> [#uses=3]
-
-declare i32 @func_15(i16 signext , i16 signext , i32) nounwind
-
-define void @func_9_entry_2E_ce(i8 %p_11) nounwind {
-newFuncRoot:
- br label %entry.ce
-
-entry.ce.ret.exitStub: ; preds = %entry.ce
- ret void
-
-entry.ce: ; preds = %newFuncRoot
- load i16* @g_3, align 2 ; <i16>:0 [#uses=1]
- icmp sgt i16 %0, 0 ; <i1>:1 [#uses=1]
- zext i1 %1 to i32 ; <i32>:2 [#uses=1]
- load i32* @g_5, align 4 ; <i32>:3 [#uses=4]
- icmp ugt i32 %2, %3 ; <i1>:4 [#uses=1]
- zext i1 %4 to i32 ; <i32>:5 [#uses=1]
- icmp eq i32 %3, 0 ; <i1>:6 [#uses=1]
- %.0 = select i1 %6, i32 1, i32 %3 ; <i32> [#uses=1]
- urem i32 1, %.0 ; <i32>:7 [#uses=2]
- sext i8 %p_11 to i16 ; <i16>:8 [#uses=1]
- trunc i32 %3 to i16 ; <i16>:9 [#uses=1]
- tail call i32 @func_15( i16 signext %8, i16 signext %9, i32 1 ) nounwind ; <i32>:10 [#uses=0]
- load i32* @g_5, align 4 ; <i32>:11 [#uses=1]
- trunc i32 %11 to i16 ; <i16>:12 [#uses=1]
- tail call i32 @func_15( i16 signext %12, i16 signext 1, i32 %7 ) nounwind ; <i32>:13 [#uses=0]
- sext i8 %p_11 to i32 ; <i32>:14 [#uses=1]
- %p_11.lobit = lshr i8 %p_11, 7 ; <i8> [#uses=1]
- %tmp = zext i8 %p_11.lobit to i32 ; <i32> [#uses=1]
- %tmp.not = xor i32 %tmp, 1 ; <i32> [#uses=1]
- %.015 = ashr i32 %14, %tmp.not ; <i32> [#uses=2]
- icmp eq i32 %.015, 0 ; <i1>:15 [#uses=1]
- %.016 = select i1 %15, i32 1, i32 %.015 ; <i32> [#uses=1]
- udiv i32 %7, %.016 ; <i32>:16 [#uses=1]
- icmp ult i32 %5, %16 ; <i1>:17 [#uses=1]
- zext i1 %17 to i32 ; <i32>:18 [#uses=1]
- store i32 %18, i32* @g_5, align 4
- br label %entry.ce.ret.exitStub
-}
Removed: llvm/trunk/test/CodeGen/X86/mcinst-lowering-cmp0.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/mcinst-lowering-cmp0.ll?rev=128844&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/mcinst-lowering-cmp0.ll (original)
+++ llvm/trunk/test/CodeGen/X86/mcinst-lowering-cmp0.ll (removed)
@@ -1,68 +0,0 @@
-; RUN: llc --show-mc-encoding -relocation-model=pic -disable-fp-elim -O3 < %s | FileCheck %s
-
-target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32"
-target triple = "i386-apple-darwin10.0.0"
-
-%struct.NSConstantString = type { i32*, i32, i8*, i32 }
-%struct._objc_module = type { i32, i32, i8*, %struct._objc_symtab* }
-%struct._objc_symtab = type { i32, i8*, i16, i16, [0 x i8*] }
-
-@"\01L_OBJC_IMAGE_INFO" = internal constant [2 x i32] [i32 0, i32 16], section "__OBJC, __image_info,regular" ; <[2 x i32]*> [#uses=1]
-@"\01L_OBJC_METH_VAR_NAME_" = internal global [4 x i8] c"foo\00", section "__TEXT,__cstring,cstring_literals", align 1 ; <[4 x i8]*> [#uses=1]
-@"\01L_OBJC_SELECTOR_REFERENCES_" = internal global i8* getelementptr inbounds ([4 x i8]* @"\01L_OBJC_METH_VAR_NAME_", i32 0, i32 0), section "__OBJC,__message_refs,literal_pointers,no_dead_strip", align 4 ; <i8**> [#uses=3]
- at __CFConstantStringClassReference = external global [0 x i32] ; <[0 x i32]*> [#uses=1]
- at .str = private constant [3 x i8] c"||\00" ; <[3 x i8]*> [#uses=1]
- at _unnamed_cfstring_ = private constant %struct.NSConstantString { i32* getelementptr inbounds ([0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 1992, i8* getelementptr inbounds ([3 x i8]* @.str, i32 0, i32 0), i32 2 }, section "__DATA,__cfstring" ; <%struct.NSConstantString*> [#uses=1]
-@"\01L_OBJC_METH_VAR_NAME_1" = internal global [5 x i8] c"baz:\00", section "__TEXT,__cstring,cstring_literals", align 1 ; <[5 x i8]*> [#uses=1]
-@"\01L_OBJC_SELECTOR_REFERENCES_2" = internal global i8* getelementptr inbounds ([5 x i8]* @"\01L_OBJC_METH_VAR_NAME_1", i32 0, i32 0), section "__OBJC,__message_refs,literal_pointers,no_dead_strip", align 4 ; <i8**> [#uses=2]
-@"\01L_OBJC_METH_VAR_NAME_3" = internal global [4 x i8] c"bar\00", section "__TEXT,__cstring,cstring_literals", align 1 ; <[4 x i8]*> [#uses=1]
-@"\01L_OBJC_SELECTOR_REFERENCES_4" = internal global i8* getelementptr inbounds ([4 x i8]* @"\01L_OBJC_METH_VAR_NAME_3", i32 0, i32 0), section "__OBJC,__message_refs,literal_pointers,no_dead_strip", align 4 ; <i8**> [#uses=2]
-@"\01L_OBJC_CLASS_NAME_" = internal global [1 x i8] zeroinitializer, section "__TEXT,__cstring,cstring_literals", align 1 ; <[1 x i8]*> [#uses=1]
-@"\01L_OBJC_MODULES" = internal global %struct._objc_module { i32 7, i32 16, i8* getelementptr inbounds ([1 x i8]* @"\01L_OBJC_CLASS_NAME_", i32 0, i32 0), %struct._objc_symtab* null }, section "__OBJC,__module_info,regular,no_dead_strip", align 4 ; <%struct._objc_module*> [#uses=1]
- at llvm.used = appending global [9 x i8*] [i8* bitcast ([2 x i32]* @"\01L_OBJC_IMAGE_INFO" to i8*), i8* getelementptr inbounds ([4 x i8]* @"\01L_OBJC_METH_VAR_NAME_", i32 0, i32 0), i8* bitcast (i8** @"\01L_OBJC_SELECTOR_REFERENCES_" to i8*), i8* getelementptr inbounds ([5 x i8]* @"\01L_OBJC_METH_VAR_NAME_1", i32 0, i32 0), i8* bitcast (i8** @"\01L_OBJC_SELECTOR_REFERENCES_2" to i8*), i8* getelementptr inbounds ([4 x i8]* @"\01L_OBJC_METH_VAR_NAME_3", i32 0, i32 0), i8* bitcast (i8** @"\01L_OBJC_SELECTOR_REFERENCES_4" to i8*), i8* getelementptr inbounds ([1 x i8]* @"\01L_OBJC_CLASS_NAME_", i32 0, i32 0), i8* bitcast (%struct._objc_module* @"\01L_OBJC_MODULES" to i8*)], section "llvm.metadata" ; <[9 x i8*]*> [#uses=0]
-
-define void @f0(i8* nocapture %a, i8* nocapture %b) nounwind optsize ssp {
-entry:
- %call = tail call i32 (...)* @get_name() nounwind optsize ; <i32> [#uses=2]
- %conv = inttoptr i32 %call to i8* ; <i8*> [#uses=1]
- %call1 = tail call i32 (...)* @get_dict() nounwind optsize ; <i32> [#uses=2]
- %conv2 = inttoptr i32 %call1 to i8* ; <i8*> [#uses=2]
-
-; Check that we lower to the short form of cmpl, which has an 8-bit immediate.
-;
-; CHECK: cmpl $0, -16(%ebp) ## 4-byte Folded Reload
-; CHECK: ## encoding: [0x83,0x7d,0xf0,0x00]
-; rdar://7999130
- %cmp = icmp eq i32 %call1, 0 ; <i1> [#uses=1]
- br i1 %cmp, label %if.end, label %if.then
-
-if.then: ; preds = %entry
- %tmp5 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_" ; <i8*> [#uses=1]
- %call6 = tail call i8* (i8*, i8*, ...)* @objc_msgSend(i8* %conv2, i8* %tmp5) nounwind optsize ; <i8*> [#uses=1]
- %tmp7 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_2" ; <i8*> [#uses=1]
- %call820 = tail call i8* (i8*, i8*, ...)* @objc_msgSend(i8* %call6, i8* %tmp7, i8* bitcast (%struct.NSConstantString* @_unnamed_cfstring_ to i8*)) nounwind optsize ; <i8*> [#uses=0]
- br label %if.end
-
-if.end: ; preds = %entry, %if.then
- %tmp10 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_" ; <i8*> [#uses=1]
- %call11 = tail call i8* (i8*, i8*, ...)* @objc_msgSend(i8* %conv2, i8* %tmp10) nounwind optsize ; <i8*> [#uses=1]
- %tmp12 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_4" ; <i8*> [#uses=1]
- %call13 = tail call i8* (i8*, i8*, ...)* @objc_msgSend(i8* %call11, i8* %tmp12) nounwind optsize ; <i8*> [#uses=0]
- %cmp15 = icmp eq i32 %call, 0 ; <i1> [#uses=1]
- br i1 %cmp15, label %if.end19, label %if.then17
-
-if.then17: ; preds = %if.end
- tail call void (...)* @f1(i8* %conv) nounwind optsize
- ret void
-
-if.end19: ; preds = %if.end
- ret void
-}
-
-declare i32 @get_name(...) optsize
-
-declare i32 @get_dict(...) optsize
-
-declare i8* @objc_msgSend(i8*, i8*, ...)
-
-declare void @f1(...) optsize
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