llvm-6502/test/Transforms/IndVarSimplify/preserve-gep.ll
Dan Gohman 5be18e8476 Teach SCEVExpander to expand arithmetic involving pointers into GEP
instructions. It attempts to create high-level multi-operand GEPs,
though in cases where this isn't possible it falls back to casting
the pointer to i8* and emitting a GEP with that. Using GEP instructions
instead of ptrtoint+arithmetic+inttoptr helps pointer analyses that
don't use ScalarEvolution, such as BasicAliasAnalysis.

Also, make the AddrModeMatcher more aggressive in handling GEPs.
Previously it assumed that operand 0 of a GEP would require a register
in almost all cases. It now does extra checking and can do more
matching if operand 0 of the GEP is foldable. This fixes a problem
that was exposed by SCEVExpander using GEPs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72093 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-19 02:15:55 +00:00

40 lines
1.3 KiB
LLVM

; RUN: llvm-as < %s | opt -indvars | llvm-dis > %t
; RUN: not grep ptrtoint %t
; RUN: not grep inttoptr %t
; RUN: grep getelementptr %t | count 1
; Indvars shouldn't leave getelementptrs expanded out as
; inttoptr+ptrtoint in its output in common cases.
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
target triple = "x86_64-unknown-linux-gnu"
%struct.Foo = type { i32, i32, [10 x i32], i32 }
define void @me(%struct.Foo* nocapture %Bar) nounwind {
entry:
br i1 false, label %return, label %bb.nph
bb.nph: ; preds = %entry
br label %bb
bb: ; preds = %bb1, %bb.nph
%i.01 = phi i64 [ %4, %bb1 ], [ 0, %bb.nph ] ; <i64> [#uses=3]
%0 = getelementptr %struct.Foo* %Bar, i64 %i.01, i32 2, i64 3 ; <i32*> [#uses=1]
%1 = load i32* %0, align 4 ; <i32> [#uses=1]
%2 = mul i32 %1, 113 ; <i32> [#uses=1]
%3 = getelementptr %struct.Foo* %Bar, i64 %i.01, i32 2, i64 3 ; <i32*> [#uses=1]
store i32 %2, i32* %3, align 4
%4 = add i64 %i.01, 1 ; <i64> [#uses=2]
br label %bb1
bb1: ; preds = %bb
%phitmp = icmp sgt i64 %4, 19999 ; <i1> [#uses=1]
br i1 %phitmp, label %bb1.return_crit_edge, label %bb
bb1.return_crit_edge: ; preds = %bb1
br label %return
return: ; preds = %bb1.return_crit_edge, %entry
ret void
}