[llvm-commits] [llvm] r94775 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineCalls.cpp test/Transforms/InstCombine/objsize.ll
Eric Christopher
echristo at apple.com
Thu Jan 28 17:09:57 PST 2010
Author: echristo
Date: Thu Jan 28 19:09:57 2010
New Revision: 94775
URL: http://llvm.org/viewvc/llvm-project?rev=94775&view=rev
Log:
Add constant support to object size handling and remove default
lowering. We'll either figure it out, or not and be lowered by
SelectionDAGBuild.
Add test.
Added:
llvm/trunk/test/Transforms/InstCombine/objsize.ll
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp?rev=94775&r1=94774&r2=94775&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp Thu Jan 28 19:09:57 2010
@@ -633,16 +633,42 @@
break;
}
case Intrinsic::objectsize: {
- ConstantInt *Const = cast<ConstantInt>(II->getOperand(2));
- const Type *Ty = CI.getType();
+ const Type *ReturnTy = CI.getType();
+ Value *Op1 = II->getOperand(1);
+
+ // If we're a constant expr then we just return the number of bytes
+ // left in whatever we're indexing. Since it's constant there's no
+ // need for maximum or minimum bytes.
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Op1)) {
+ // If this isn't a GEP give up.
+ if (CE->getOpcode() != Instruction::GetElementPtr) return 0;
+
+ const PointerType *ObjTy =
+ reinterpret_cast<const PointerType*>(CE->getOperand(0)->getType());
+
+ if (const ArrayType *AT = dyn_cast<ArrayType>(ObjTy->getElementType())) {
+
+ // Deal with multi-dimensional arrays
+ const ArrayType *SAT = AT;
+ while ((AT = dyn_cast<ArrayType>(AT->getElementType())))
+ SAT = AT;
+
+ size_t numElems = SAT->getNumElements();
+ // We return the remaining bytes, so grab the size of an element
+ // in bytes.
+ size_t sizeofElem = SAT->getElementType()->getPrimitiveSizeInBits() / 8;
+
+ ConstantInt *Const =
+ cast<ConstantInt>(CE->getOperand(CE->getNumOperands() - 1));
+ size_t indx = Const->getZExtValue();
+ return ReplaceInstUsesWith(CI,
+ ConstantInt::get(ReturnTy,
+ ((numElems - indx) * sizeofElem)));
+ }
+ }
- // 0 is maximum number of bytes left, 1 is minimum number of bytes left.
- // TODO: actually add these values, the current return values are "don't
- // know".
- if (Const->getZExtValue() == 0)
- return ReplaceInstUsesWith(CI, Constant::getAllOnesValue(Ty));
- else
- return ReplaceInstUsesWith(CI, ConstantInt::get(Ty, 0));
+ // TODO: Add more Instruction types here.
+
}
}
Added: llvm/trunk/test/Transforms/InstCombine/objsize.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/objsize.ll?rev=94775&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/objsize.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/objsize.ll Thu Jan 28 19:09:57 2010
@@ -0,0 +1,30 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+ at a = common global [60 x i8] zeroinitializer, align 1 ; <[60 x i8]*>
+ at .str = private constant [8 x i8] c"abcdefg\00" ; <[8 x i8]*>
+
+define i32 @foo() nounwind {
+; CHECK: @foo
+; CHECK-NEXT: ret i32 60
+ %1 = call i32 @llvm.objectsize.i32(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i1 false)
+ ret i32 %1
+}
+
+define i8* @bar() nounwind {
+; CHECK: @bar
+entry:
+ %retval = alloca i8*
+ %0 = call i32 @llvm.objectsize.i32(i8* getelementptr inbounds ([60 x i8]* @a, i32 0, i32 0), i1 false)
+ %cmp = icmp ne i32 %0, -1
+; CHECK: br i1 true
+ br i1 %cmp, label %cond.true, label %cond.false
+
+cond.true:
+ %1 = load i8** %retval;
+ ret i8* %1;
+
+cond.false:
+ %2 = load i8** %retval;
+ ret i8* %2;
+}
+
+declare i32 @llvm.objectsize.i32(i8*, i1) nounwind readonly
\ No newline at end of file
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