[llvm-commits] [llvm] r159876 - in /llvm/trunk: lib/Transforms/InstCombine/InstructionCombining.cpp test/Transforms/InstCombine/badmalloc.ll test/Transforms/InstCombine/invoke.ll test/Transforms/InstCombine/malloc-free-delete.ll test/Transforms/InstCombine/objsize-64.ll test/Transforms/InstCombine/objsize.ll
Nuno Lopes
nunoplopes at sapo.pt
Fri Jul 6 16:09:25 PDT 2012
Author: nlopes
Date: Fri Jul 6 18:09:25 2012
New Revision: 159876
URL: http://llvm.org/viewvc/llvm-project?rev=159876&view=rev
Log:
teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users.
This means we can do cheap DSE for heap memory.
Nothing is done if the pointer excapes or has a load.
The churn in the tests is mostly due to objectsize, since we want to make sure we
don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0)
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
llvm/trunk/test/Transforms/InstCombine/badmalloc.ll
llvm/trunk/test/Transforms/InstCombine/invoke.ll
llvm/trunk/test/Transforms/InstCombine/malloc-free-delete.ll
llvm/trunk/test/Transforms/InstCombine/objsize-64.ll
llvm/trunk/test/Transforms/InstCombine/objsize.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp?rev=159876&r1=159875&r2=159876&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp Fri Jul 6 18:09:25 2012
@@ -1137,12 +1137,29 @@
}
}
if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U)) {
- if (II->getIntrinsicID() == Intrinsic::lifetime_start ||
- II->getIntrinsicID() == Intrinsic::lifetime_end) {
+ switch (II->getIntrinsicID()) {
+ default: return false;
+ case Intrinsic::memmove:
+ case Intrinsic::memcpy:
+ case Intrinsic::memset: {
+ MemIntrinsic *MI = cast<MemIntrinsic>(II);
+ if (MI->isVolatile() || MI->getRawDest() != V)
+ return false;
+ }
+ // fall through
+ case Intrinsic::objectsize:
+ case Intrinsic::lifetime_start:
+ case Intrinsic::lifetime_end:
Users.push_back(II);
continue;
}
}
+ if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
+ if (SI->isVolatile() || SI->getPointerOperand() != V)
+ return false;
+ Users.push_back(SI);
+ continue;
+ }
return false;
}
return true;
@@ -1164,6 +1181,12 @@
C->isFalseWhenEqual()));
} else if (isa<BitCastInst>(I) || isa<GetElementPtrInst>(I)) {
ReplaceInstUsesWith(*I, UndefValue::get(I->getType()));
+ } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
+ if (II->getIntrinsicID() == Intrinsic::objectsize) {
+ ConstantInt *CI = cast<ConstantInt>(II->getArgOperand(1));
+ uint64_t DontKnow = CI->isZero() ? -1ULL : 0;
+ ReplaceInstUsesWith(*I, ConstantInt::get(I->getType(), DontKnow));
+ }
}
EraseInstFromFunction(*I);
}
Modified: llvm/trunk/test/Transforms/InstCombine/badmalloc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/badmalloc.ll?rev=159876&r1=159875&r2=159876&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/badmalloc.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/badmalloc.ll Fri Jul 6 18:09:25 2012
@@ -16,5 +16,26 @@
ret i1 %B
; CHECK: @test1
-; CHECK: ret i1 %B
+; CHECK: ret i1 false
+}
+
+; CHECK: @test2
+define noalias i8* @test2() nounwind {
+entry:
+; CHECK: @malloc
+ %A = call noalias i8* @malloc(i64 4) nounwind
+; CHECK: icmp eq
+ %tobool = icmp eq i8* %A, null
+; CHECK: br i1
+ br i1 %tobool, label %return, label %if.end
+
+if.end:
+; CHECK: store
+ store i8 7, i8* %A
+ br label %return
+
+return:
+; CHECK: phi
+ %retval.0 = phi i8* [ %A, %if.end ], [ null, %entry ]
+ ret i8* %retval.0
}
Modified: llvm/trunk/test/Transforms/InstCombine/invoke.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/invoke.ll?rev=159876&r1=159875&r2=159876&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/invoke.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/invoke.ll Fri Jul 6 18:09:25 2012
@@ -4,6 +4,7 @@
declare i32 @__gxx_personality_v0(...)
declare void @__cxa_call_unexpected(i8*)
declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readonly
+declare i8* @_Znwm(i64)
; CHECK: @f1
@@ -45,3 +46,20 @@
tail call void @__cxa_call_unexpected(i8* %2) noreturn nounwind
unreachable
}
+
+; CHECK: @f3
+define void @f3() nounwind uwtable ssp {
+; CHECK: invoke void @llvm.donothing()
+ %call = invoke noalias i8* @_Znwm(i64 13)
+ to label %invoke.cont unwind label %lpad
+
+invoke.cont:
+ ret void
+
+lpad:
+ %1 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ filter [0 x i8*] zeroinitializer
+ %2 = extractvalue { i8*, i32 } %1, 0
+ tail call void @__cxa_call_unexpected(i8* %2) noreturn nounwind
+ unreachable
+}
Modified: llvm/trunk/test/Transforms/InstCombine/malloc-free-delete.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/malloc-free-delete.ll?rev=159876&r1=159875&r2=159876&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/malloc-free-delete.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/malloc-free-delete.ll Fri Jul 6 18:09:25 2012
@@ -1,17 +1,17 @@
; RUN: opt < %s -instcombine -S | FileCheck %s
; PR1201
define i32 @main(i32 %argc, i8** %argv) {
+; CHECK: @main
%c_19 = alloca i8*
%malloc_206 = tail call i8* @malloc(i32 mul (i32 ptrtoint (i8* getelementptr (i8* null, i32 1) to i32), i32 10))
store i8* %malloc_206, i8** %c_19
%tmp_207 = load i8** %c_19
tail call void @free(i8* %tmp_207)
ret i32 0
-; CHECK-NOT: malloc
-; CHECK-NOT: free
-; CHECK: ret i32 0
+; CHECK-NEXT: ret i32 0
}
+declare noalias i8* @calloc(i32, i32) nounwind
declare noalias i8* @malloc(i32)
declare void @free(i8*)
@@ -26,13 +26,24 @@
declare void @llvm.lifetime.start(i64, i8*)
declare void @llvm.lifetime.end(i64, i8*)
+declare i64 @llvm.objectsize.i64(i8*, i1)
+declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
+declare void @llvm.memmove.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
+declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i32, i1) nounwind
-define void @test3() {
+define void @test3(i8* %src) {
; CHECK: @test3
; CHECK-NEXT: ret void
%a = call noalias i8* @malloc(i32 10)
call void @llvm.lifetime.start(i64 10, i8* %a)
call void @llvm.lifetime.end(i64 10, i8* %a)
+ %size = call i64 @llvm.objectsize.i64(i8* %a, i1 true)
+ store i8 42, i8* %a
+ call void @llvm.memcpy.p0i8.p0i8.i32(i8* %a, i8* %src, i32 32, i32 1, i1 false)
+ call void @llvm.memmove.p0i8.p0i8.i32(i8* %a, i8* %src, i32 32, i32 1, i1 false)
+ call void @llvm.memset.p0i8.i32(i8* %a, i8 5, i32 32, i32 1, i1 false)
+ %alloc2 = call noalias i8* @calloc(i32 5, i32 7) nounwind
+ %z = icmp ne i8* %alloc2, null
ret void
}
@@ -46,3 +57,37 @@
call void @free(i8* %C)
ret void
}
+
+; CHECK: @test5
+define void @test5(i8* %ptr, i8** %esc) {
+; CHECK-NEXT: call i8* @malloc
+; CHECK-NEXT: call i8* @malloc
+; CHECK-NEXT: call i8* @malloc
+; CHECK-NEXT: call i8* @malloc
+; CHECK-NEXT: call i8* @malloc
+; CHECK-NEXT: call i8* @malloc
+; CHECK-NEXT: call i8* @malloc
+; CHECK-NEXT: call void @llvm.memcpy
+; CHECK-NEXT: call void @llvm.memmove
+; CHECK-NEXT: store
+; CHECK-NEXT: call void @llvm.memcpy
+; CHECK-NEXT: call void @llvm.memmove
+; CHECK-NEXT: call void @llvm.memset
+; CHECK-NEXT: store volatile
+; CHECK-NEXT: ret
+ %a = call i8* @malloc(i32 700)
+ %b = call i8* @malloc(i32 700)
+ %c = call i8* @malloc(i32 700)
+ %d = call i8* @malloc(i32 700)
+ %e = call i8* @malloc(i32 700)
+ %f = call i8* @malloc(i32 700)
+ %g = call i8* @malloc(i32 700)
+ call void @llvm.memcpy.p0i8.p0i8.i32(i8* %ptr, i8* %a, i32 32, i32 1, i1 false)
+ call void @llvm.memmove.p0i8.p0i8.i32(i8* %ptr, i8* %b, i32 32, i32 1, i1 false)
+ store i8* %c, i8** %esc
+ call void @llvm.memcpy.p0i8.p0i8.i32(i8* %d, i8* %ptr, i32 32, i32 1, i1 true)
+ call void @llvm.memmove.p0i8.p0i8.i32(i8* %e, i8* %ptr, i32 32, i32 1, i1 true)
+ call void @llvm.memset.p0i8.i32(i8* %f, i8 5, i32 32, i32 1, i1 true)
+ store volatile i8 4, i8* %g
+ ret void
+}
Modified: llvm/trunk/test/Transforms/InstCombine/objsize-64.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/objsize-64.ll?rev=159876&r1=159875&r2=159876&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/objsize-64.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/objsize-64.ll Fri Jul 6 18:09:25 2012
@@ -8,23 +8,25 @@
declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readonly
; CHECK: @f1
-define i64 @f1() {
+define i64 @f1(i8 **%esc) {
%call = call i8* @malloc(i32 4)
+ store i8* %call, i8** %esc
%size = call i64 @llvm.objectsize.i64(i8* %call, i1 false)
-; CHECK-NEXT: ret i64 4
+; CHECK: ret i64 4
ret i64 %size
}
; CHECK: @f2
-define i64 @f2() nounwind uwtable ssp {
+define i64 @f2(i8** %esc) nounwind uwtable ssp {
entry:
-; CHECK: invoke void @llvm.donothing()
+; CHECK: invoke noalias i8* @_Znwm(i64 13)
%call = invoke noalias i8* @_Znwm(i64 13)
to label %invoke.cont unwind label %lpad
invoke.cont:
; CHECK: ret i64 13
+ store i8* %call, i8** %esc
%0 = tail call i64 @llvm.objectsize.i64(i8* %call, i1 false)
ret i64 %0
Modified: llvm/trunk/test/Transforms/InstCombine/objsize.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/objsize.ll?rev=159876&r1=159875&r2=159876&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/objsize.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/objsize.ll Fri Jul 6 18:09:25 2012
@@ -121,7 +121,7 @@
; rdar://7782496
@s = external global i8*
-define void @test5(i32 %n) nounwind ssp {
+define i8* @test5(i32 %n) nounwind ssp {
; CHECK: @test5
entry:
%0 = tail call noalias i8* @malloc(i32 20) nounwind
@@ -130,7 +130,7 @@
; CHECK-NOT: @llvm.objectsize
; CHECK: @llvm.memcpy.p0i8.p0i8.i32(i8* %0, i8* %1, i32 10, i32 1, i1 false)
%3 = tail call i8* @__memcpy_chk(i8* %0, i8* %2, i32 10, i32 %1) nounwind
- ret void
+ ret i8* %0
}
define void @test6(i32 %n) nounwind ssp {
@@ -149,22 +149,24 @@
declare noalias i8* @malloc(i32) nounwind
-define i32 @test7() {
+define i32 @test7(i8** %esc) {
; CHECK: @test7
%alloc = call noalias i8* @malloc(i32 48) nounwind
+ store i8* %alloc, i8** %esc
%gep = getelementptr inbounds i8* %alloc, i32 16
%objsize = call i32 @llvm.objectsize.i32(i8* %gep, i1 false) nounwind readonly
-; CHECK-NEXT: ret i32 32
+; CHECK: ret i32 32
ret i32 %objsize
}
declare noalias i8* @calloc(i32, i32) nounwind
-define i32 @test8() {
+define i32 @test8(i8** %esc) {
; CHECK: @test8
%alloc = call noalias i8* @calloc(i32 5, i32 7) nounwind
+ store i8* %alloc, i8** %esc
%gep = getelementptr inbounds i8* %alloc, i32 5
%objsize = call i32 @llvm.objectsize.i32(i8* %gep, i1 false) nounwind readonly
-; CHECK-NEXT: ret i32 30
+; CHECK: ret i32 30
ret i32 %objsize
}
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