Commit 5fb1963f authored by Nick Lewycky's avatar Nick Lewycky
Browse files

Fix a bug in codegenprep where it was losing track of values OptimizeMemoryInst 

by switching to a ValueMap. Patch by Andrea DiBiagio!

llvm-svn: 181397
parent bb5a17e8

llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp

+2 −5
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include "llvm/ADT/DenseMap.h"

#include "llvm/ADT/SmallSet.h"

#include "llvm/ADT/Statistic.h"

#include "llvm/ADT/ValueMap.h"

#include "llvm/Analysis/DominatorInternals.h"

#include "llvm/Analysis/Dominators.h"

#include "llvm/Analysis/InstructionSimplify.h"
@@ -88,7 +89,7 @@ namespace { 
    /// Keeps track of non-local addresses that have been sunk into a block.

    /// This allows us to avoid inserting duplicate code for blocks with

    /// multiple load/stores of the same address.

    DenseMap<Value*, Value*> SunkAddrs;

    ValueMap<Value*, Value*> SunkAddrs;



    /// ModifiedDT - If CFG is modified in anyway, dominator tree may need to

    /// be updated.
@@ -1653,10 +1654,6 @@ bool CodeGenPrepare::OptimizeMemoryInst(Instruction *MemoryInst, Value *Addr, 
      // start of the block.

      CurInstIterator = BB->begin();

      SunkAddrs.clear();

    } else {

      // This address is now available for reassignment, so erase the table

      // entry; we don't want to match some completely different instruction.

      SunkAddrs[Addr] = 0;

    }

  }

  ++NumMemoryInsts;

llvm/test/CodeGen/X86/codegen-prepare.ll

0 → 100644
+44 −0
Original line number Diff line number Diff line 
; RUN: llc < %s -mtriple=x86_64-pc-linux | FileCheck %s



; Check that the CodeGenPrepare Pass

; does not wrongly rewrite the address computed by Instruction %4

; as [12 + Base:%this].



; This test makes sure that:

; - both the store and the first load instructions

;   within basic block labeled 'if.then' are not removed. 

; - the store instruction stores a value at address [60 + %this]

; - the first load instruction loads a value at address [12 + %this]



%class.A = type { %struct.B }

%struct.B = type { %class.C, %class.D, %class.C, %class.D }

%class.C = type { float, float, float }

%class.D = type { [3 x %class.C] }



define linkonce_odr void @foo(%class.A* nocapture %this, i32 %BoolValue) nounwind uwtable {

entry:

  %cmp = icmp eq i32 %BoolValue, 0

  %address1 = getelementptr inbounds %class.A* %this, i64 0, i32 0, i32 3

  %address2 = getelementptr inbounds %class.A* %this, i64 0, i32 0, i32 1

  br i1 %cmp, label %if.else, label %if.then



if.then:                                         ; preds = %entry

  %0 = getelementptr inbounds %class.D* %address2, i64 0, i32 0, i64 0, i32 0

  %1 = load float* %0, align 4 

  %2 = getelementptr inbounds float* %0, i64 3

  %3 = load float* %2, align 4 

  %4 = getelementptr inbounds %class.D* %address1, i64 0, i32 0, i64 0, i32 0

  store float %1, float* %4, align 4

  br label %if.end



if.else:                                          ; preds = %entry

  br label %if.end



if.end:                                           ; preds = %if.then, %if.else, %entry

  ret void

}



; CHECK: foo:

; CHECK: movss 12([[THIS:%[a-zA-Z0-9]+]]), [[REGISTER:%[a-zA-Z0-9]+]]

; CHECK-NEXT: movss [[REGISTER]], 60([[THIS]])