[llvm-commits] [llvm] r61946 - in /llvm/trunk: include/llvm/Transforms/Utils/InlineCost.h lib/Transforms/Utils/InlineCost.cpp test/Transforms/Inline/2009-01-08-NoInlineDynamicAlloca.ll test/Transforms/Inline/dynamic_alloca_test.ll test/Transforms/PruneEH/2008-09-05-CGUpdate.ll
Dale Johannesen
dalej at apple.com
Thu Jan 8 13:45:23 PST 2009
Author: johannes
Date: Thu Jan 8 15:45:23 2009
New Revision: 61946
URL: http://llvm.org/viewvc/llvm-project?rev=61946&view=rev
Log:
Do not inline functions with (dynamic) alloca into
functions that don't already have a (dynamic) alloca.
Dynamic allocas cause inefficient codegen and we shouldn't
propagate this (behavior follows gcc). Two existing tests
assumed such inlining would be done; they are hacked by
adding an alloca in the caller, preserving the point of
the tests.
Added:
llvm/trunk/test/Transforms/Inline/2009-01-08-NoInlineDynamicAlloca.ll
Modified:
llvm/trunk/include/llvm/Transforms/Utils/InlineCost.h
llvm/trunk/lib/Transforms/Utils/InlineCost.cpp
llvm/trunk/test/Transforms/Inline/dynamic_alloca_test.ll
llvm/trunk/test/Transforms/PruneEH/2008-09-05-CGUpdate.ll
Modified: llvm/trunk/include/llvm/Transforms/Utils/InlineCost.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/InlineCost.h?rev=61946&r1=61945&r2=61946&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/InlineCost.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/InlineCost.h Thu Jan 8 15:45:23 2009
@@ -78,6 +78,9 @@
/// caller.
bool NeverInline;
+ /// usesDynamicAlloca - True if this function calls alloca (in the C sense).
+ bool usesDynamicAlloca;
+
/// NumInsts, NumBlocks - Keep track of how large each function is, which
/// is used to estimate the code size cost of inlining it.
unsigned NumInsts, NumBlocks;
@@ -93,8 +96,8 @@
/// entry here.
std::vector<ArgInfo> ArgumentWeights;
- FunctionInfo() : NeverInline(false), NumInsts(0), NumBlocks(0),
- NumVectorInsts(0) {}
+ FunctionInfo() : NeverInline(false), usesDynamicAlloca(false), NumInsts(0),
+ NumBlocks(0), NumVectorInsts(0) {}
/// analyzeFunction - Fill in the current structure with information
/// gleaned from the specified function.
Modified: llvm/trunk/lib/Transforms/Utils/InlineCost.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/InlineCost.cpp?rev=61946&r1=61945&r2=61946&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/InlineCost.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/InlineCost.cpp Thu Jan 8 15:45:23 2009
@@ -126,6 +126,11 @@
NumInsts += 5;
}
+ if (const AllocaInst *AI = dyn_cast<AllocaInst>(II)) {
+ if (!isa<ConstantInt>(AI->getArraySize()))
+ this->usesDynamicAlloca = true;
+ }
+
if (isa<ExtractElementInst>(II) || isa<VectorType>(II->getType()))
++NumVectorInsts;
@@ -173,7 +178,7 @@
SmallPtrSet<const Function *, 16> &NeverInline) {
Instruction *TheCall = CS.getInstruction();
Function *Callee = CS.getCalledFunction();
- const Function *Caller = TheCall->getParent()->getParent();
+ Function *Caller = TheCall->getParent()->getParent();
// Don't inline a directly recursive call.
if (Caller == Callee ||
@@ -219,11 +224,24 @@
// If we haven't calculated this information yet, do so now.
if (CalleeFI.NumBlocks == 0)
CalleeFI.analyzeFunction(Callee);
-
+
// If we should never inline this, return a huge cost.
if (CalleeFI.NeverInline)
return InlineCost::getNever();
+ // Get infomation about the caller...
+ FunctionInfo &CallerFI = CachedFunctionInfo[Caller];
+
+ // If we haven't calculated this information yet, do so now.
+ if (CallerFI.NumBlocks == 0)
+ CallerFI.analyzeFunction(Caller);
+
+ // Don't inline a callee with dynamic alloca into a caller without them.
+ // Functions containing dynamic alloca's are inefficient in various ways;
+ // don't create more inefficiency.
+ if (CalleeFI.usesDynamicAlloca && !CallerFI.usesDynamicAlloca)
+ return InlineCost::getNever();
+
// FIXME: It would be nice to kill off CalleeFI.NeverInline. Then we
// could move this up and avoid computing the FunctionInfo for
// things we are going to just return always inline for. This
Added: llvm/trunk/test/Transforms/Inline/2009-01-08-NoInlineDynamicAlloca.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Inline/2009-01-08-NoInlineDynamicAlloca.ll?rev=61946&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Inline/2009-01-08-NoInlineDynamicAlloca.ll (added)
+++ llvm/trunk/test/Transforms/Inline/2009-01-08-NoInlineDynamicAlloca.ll Thu Jan 8 15:45:23 2009
@@ -0,0 +1,36 @@
+; RUN: llvm-as < %s | opt -inline | llvm-dis | grep call
+; Do not inline calls to variable-sized alloca.
+
+ at q = common global i8* null ; <i8**> [#uses=1]
+
+define i8* @a(i32 %i) nounwind {
+entry:
+ %i_addr = alloca i32 ; <i32*> [#uses=2]
+ %retval = alloca i8* ; <i8**> [#uses=1]
+ %p = alloca i8* ; <i8**> [#uses=2]
+ %"alloca point" = bitcast i32 0 to i32 ; <i32> [#uses=0]
+ store i32 %i, i32* %i_addr
+ %0 = load i32* %i_addr, align 4 ; <i32> [#uses=1]
+ %1 = alloca i8, i32 %0 ; <i8*> [#uses=1]
+ store i8* %1, i8** %p, align 4
+ %2 = load i8** %p, align 4 ; <i8*> [#uses=1]
+ store i8* %2, i8** @q, align 4
+ br label %return
+
+return: ; preds = %entry
+ %retval1 = load i8** %retval ; <i8*> [#uses=1]
+ ret i8* %retval1
+}
+
+define void @b(i32 %i) nounwind {
+entry:
+ %i_addr = alloca i32 ; <i32*> [#uses=2]
+ %"alloca point" = bitcast i32 0 to i32 ; <i32> [#uses=0]
+ store i32 %i, i32* %i_addr
+ %0 = load i32* %i_addr, align 4 ; <i32> [#uses=1]
+ %1 = call i8* @a(i32 %0) nounwind ; <i8*> [#uses=0]
+ br label %return
+
+return: ; preds = %entry
+ ret void
+}
Modified: llvm/trunk/test/Transforms/Inline/dynamic_alloca_test.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Inline/dynamic_alloca_test.ll?rev=61946&r1=61945&r2=61946&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/Inline/dynamic_alloca_test.ll (original)
+++ llvm/trunk/test/Transforms/Inline/dynamic_alloca_test.ll Thu Jan 8 15:45:23 2009
@@ -1,5 +1,7 @@
; Test that functions with dynamic allocas get inlined in a case where
; naively inlining it would result in a miscompilation.
+; Functions with dynamic allocas can only be inlined into functions that
+; already have dynamic allocas.
; RUN: llvm-as < %s | opt -inline | llvm-dis | \
; RUN: grep llvm.stacksave
@@ -16,6 +18,8 @@
define void @foo(i32 %N) {
; <label>:0
+ %P = alloca i32, i32 %N ; <i32*> [#uses=1]
+ call void @ext( i32* %P )
br label %Loop
Loop: ; preds = %Loop, %0
Modified: llvm/trunk/test/Transforms/PruneEH/2008-09-05-CGUpdate.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/PruneEH/2008-09-05-CGUpdate.ll?rev=61946&r1=61945&r2=61946&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/PruneEH/2008-09-05-CGUpdate.ll (original)
+++ llvm/trunk/test/Transforms/PruneEH/2008-09-05-CGUpdate.ll Thu Jan 8 15:45:23 2009
@@ -636,6 +636,9 @@
define internal fastcc i32 @ce3806g__fxio__put__4.1215(i8* %to.0, %struct.string___XUB* %to.1, i8 signext %item) {
entry:
+ %P0 = load i32 * @__gnat_all_others_value, align 4 ; <i32*> [#uses=1]
+ %P = alloca i32, i32 %P0 ; <i32*> [#uses=1]
+ call void @ext( i32* %P )
%to_addr = alloca %struct.system__file_control_block__pstring ; <%struct.system__file_control_block__pstring*> [#uses=4]
%FRAME.358 = alloca %struct.FRAME.ce3806g__fxio__put__4 ; <%struct.FRAME.ce3806g__fxio__put__4*> [#uses=65]
%0 = getelementptr %struct.system__file_control_block__pstring* %to_addr, i32 0, i32 0 ; <i8**> [#uses=1]
@@ -1435,6 +1438,8 @@
declare void @report__failed(i8*, %struct.string___XUB*)
+declare void @ext(i32*)
+
declare %struct.ada__text_io__text_afcb* @ada__text_io__delete(%struct.ada__text_io__text_afcb*)
declare void @report__result()
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