[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

Duncan Sands baldrick at free.fr
Sat Jul 7 00:17:59 PDT 2012


Hi Nuno,

> --- 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)

why exclude volatile stores?  If all that is being done to the allocated memory
is doing a bunch of volatile stores to it, I don't see why you can't discard
them and the allocation too.

Ciao, Duncan.

> +          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
>   }
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>





More information about the llvm-commits mailing list