fix PR3537: if resetting bbi back to the start of a block, we need to

forget about already inserted expressions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64362 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/CodeGenPrepare.cpp b/lib/Transforms/Scalar/CodeGenPrepare.cpp
index 0a1c641e2bf4ed2c97eaf3864c66d011419a3488..12c76e852514b6f7c4513951b0093bab480a07e8 100644 (file)
--- a/lib/Transforms/Scalar/CodeGenPrepare.cpp
+++ b/lib/Transforms/Scalar/CodeGenPrepare.cpp
@@ -1241,11 +1241,13 @@ bool CodeGenPrepare::OptimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
   // computation.
   Value *&SunkAddr = SunkAddrs[Addr];
   if (SunkAddr) {
-    DEBUG(cerr << "CGP: Reusing nonlocal addrmode: " << AddrMode << "\n");
+    DEBUG(cerr << "CGP: Reusing nonlocal addrmode: " << AddrMode << " for "
+               << *MemoryInst);
     if (SunkAddr->getType() != Addr->getType())
       SunkAddr = new BitCastInst(SunkAddr, Addr->getType(), "tmp", InsertPt);
   } else {
-    DEBUG(cerr << "CGP: SINKING nonlocal addrmode: " << AddrMode << "\n");
+    DEBUG(cerr << "CGP: SINKING nonlocal addrmode: " << AddrMode << " for "
+               << *MemoryInst);
     const Type *IntPtrTy = TLI->getTargetData()->getIntPtrType();
 
     Value *Result = 0;
@@ -1505,9 +1507,12 @@ bool CodeGenPrepare::OptimizeBlock(BasicBlock &BB) {
       if (TLI && isa<InlineAsm>(CI->getCalledValue()))
         if (const TargetAsmInfo *TAI =
             TLI->getTargetMachine().getTargetAsmInfo()) {
-          if (TAI->ExpandInlineAsm(CI))
+          if (TAI->ExpandInlineAsm(CI)) {
             BBI = BB.begin();
-          else
+            // Avoid processing instructions out of order, which could cause
+            // reuse before a value is defined.
+            SunkAddrs.clear();
+          } else
             // Sink address computing for memory operands into the block.
             MadeChange |= OptimizeInlineAsmInst(I, &(*CI), SunkAddrs);
         }

diff --git a/test/CodeGen/X86/2009-02-11-codegenprepare-reuse.ll b/test/CodeGen/X86/2009-02-11-codegenprepare-reuse.ll
new file mode 100644 (file)
index 0000000..7b73a86
--- /dev/null
+++ b/test/CodeGen/X86/2009-02-11-codegenprepare-reuse.ll
@@ -0,0 +1,35 @@
+; RUN: llvm-as < %s | llc
+; PR3537
+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-f80:128:128"
+target triple = "i386-apple-darwin9.6"
+       %struct.GetBitContext = type <{ i8*, i8*, i32, i32 }>
+
+define i32 @alac_decode_frame() nounwind {
+entry:
+       %tmp2 = load i8** null          ; <i8*> [#uses=2]
+       %tmp34 = getelementptr i8* %tmp2, i32 4         ; <i8*> [#uses=2]
+       %tmp5.i424 = bitcast i8* %tmp34 to i8**         ; <i8**> [#uses=2]
+       %tmp15.i = getelementptr i8* %tmp2, i32 12              ; <i8*> [#uses=1]
+       %0 = bitcast i8* %tmp15.i to i32*               ; <i32*> [#uses=1]
+       br i1 false, label %if.then43, label %if.end47
+
+if.then43:             ; preds = %entry
+       ret i32 0
+
+if.end47:              ; preds = %entry
+       %tmp5.i590 = load i8** %tmp5.i424               ; <i8*> [#uses=0]
+       store i32 19, i32* %0
+       %tmp6.i569 = load i8** %tmp5.i424               ; <i8*> [#uses=0]
+       %1 = call i32 asm "bswap   $0", "=r,0,~{dirflag},~{fpsr},~{flags}"(i32 0) nounwind              ; <i32> [#uses=0]
+       br i1 false, label %bb.nph, label %if.then63
+
+if.then63:             ; preds = %if.end47
+       unreachable
+
+bb.nph:                ; preds = %if.end47
+       %2 = bitcast i8* %tmp34 to %struct.GetBitContext*               ; <%struct.GetBitContext*> [#uses=1]
+       %call9.i = call fastcc i32 @decode_scalar(%struct.GetBitContext* %2, i32 0, i32 0, i32 0) nounwind              ; <i32> [#uses=0]
+       unreachable
+}
+
+declare fastcc i32 @decode_scalar(%struct.GetBitContext* nocapture, i32, i32, i32) nounwind