[llvm-commits] [llvm] r71535 - in /llvm/trunk: include/llvm/Analysis/ lib/Analysis/ lib/Target/ lib/Transforms/Scalar/ test/CodeGen/X86/ test/Transforms/IndVarSimplify/ test/Transforms/LoopStrengthReduce/

[Duncan Sands]

Hi Dan, thank you for doing this!

> Now that IndVarSimplify is being more aggressive, it occasionally runs
> into the problem where ScalarEvolutionExpander's code for avoiding
> duplicate expansions makes it difficult to ensure that all expanded
> instructions dominate all the instructions that will use them. As a
> temporary measure, IndVarSimplify now uses a FixUsesBeforeDefs function
> to fix up instructions inserted by SCEVExpander. Fortunately, this code
> is contained, and can be easily removed once a more comprehensive
> solution is available.

Unfortunately this causes several Ada testsuite failures.  I've attached
a reduced testcase (all the failures seem be to for the same reason).

$ opt -indvars c35503g.bc -disable-output
opt: llvm/include/llvm/ADT/ilist.h:197: typename bidirectional_iterator<NodeTy, int>::reference llvm::ilist_iterator<NodeTy>::operator*() const [with NodeTy = llvm::Instruction]: Assertion `Traits::getNext(NodePtr) != 0 && "Dereferencing end()!"' failed.
0   opt 0x08448bc8
Stack dump:
0.	Running pass 'Function Pass Manager' on module 'c35503g.bc'.
1.	Running pass 'Loop Pass Manager' on function '@_ada_c35503g'
2.	Running pass 'Canonicalize Induction Variables' on basic block '%bb123'
-------------- next part --------------
; ModuleID = 'c35503g.bc'
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-f80:32:32"
target triple = "i386-pc-linux-gnu"
	%struct.string___XUB = type { i32, i32 }
	%struct.string___XUP = type { [0 x i8]*, %struct.string___XUB* }
@.str7 = external constant [24 x i8]		; <[24 x i8]*> [#uses=1]
@C.17.316 = external constant %struct.string___XUB		; <%struct.string___XUB*> [#uses=1]

define void @_ada_c35503g() {
entry:
	br label %bb

bb:		; preds = %bb, %entry
	br i1 false, label %bb65.loopexit, label %bb

bb65.loopexit:		; preds = %bb
	br label %bb123

bb123:		; preds = %bb178, %bb65.loopexit
	%i.0 = phi i32 [ %3, %bb178 ], [ 0, %bb65.loopexit ]		; <i32> [#uses=3]
	%0 = invoke i32 @report__ident_int(i32 1)
			to label %invcont127 unwind label %lpad266		; <i32> [#uses=1]

invcont127:		; preds = %bb123
	%1 = sub i32 %i.0, %0		; <i32> [#uses=1]
	%2 = icmp eq i32 0, %1		; <i1> [#uses=1]
	br i1 %2, label %bb178, label %bb128

bb128:		; preds = %invcont127
	invoke void @system__img_int__image_integer(%struct.string___XUP* noalias sret null, i32 %i.0)
			to label %invcont129 unwind label %lpad266

invcont129:		; preds = %bb128
	invoke void @system__string_ops__str_concat(%struct.string___XUP* noalias sret null, [0 x i8]* bitcast ([24 x i8]* @.str7 to [0 x i8]*), %struct.string___XUB* @C.17.316, [0 x i8]* null, %struct.string___XUB* null)
			to label %invcont138 unwind label %lpad266

invcont138:		; preds = %invcont129
	unreachable

bb178:		; preds = %invcont127
	%3 = add i32 %i.0, 1		; <i32> [#uses=1]
	br label %bb123

lpad266:		; preds = %invcont129, %bb128, %bb123
	unreachable
}

declare void @system__img_int__image_integer(%struct.string___XUP* noalias sret, i32)

declare void @system__string_ops__str_concat(%struct.string___XUP* noalias sret, [0 x i8]*, %struct.string___XUB*, [0 x i8]*, %struct.string___XUB*)

declare i32 @report__ident_int(i32)