Handle multiple induction variables.

This fixes PR714.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42309 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/LoopIndexSplit.cpp b/lib/Transforms/Scalar/LoopIndexSplit.cpp
index 6582f368a739f8de1fb3d121309cecfa7eec062a..5064063f29ad953b02a1526054178b3312e1a431 100644 (file)
--- a/lib/Transforms/Scalar/LoopIndexSplit.cpp
+++ b/lib/Transforms/Scalar/LoopIndexSplit.cpp
@@ -676,7 +676,7 @@ bool LoopIndexSplit::safeExitingBlock(SplitInfo &SD,
       continue;
 
     // Check if I is induction variable increment instruction.
-    if (!IndVarIncrement && I->getOpcode() == Instruction::Add) {
+    if (I->getOpcode() == Instruction::Add) {
 
       Value *Op0 = I->getOperand(0);
       Value *Op1 = I->getOperand(1);
@@ -685,16 +685,23 @@ bool LoopIndexSplit::safeExitingBlock(SplitInfo &SD,
 
       if ((PN = dyn_cast<PHINode>(Op0))) {
         if ((CI = dyn_cast<ConstantInt>(Op1)))
-          IndVarIncrement = I;
+          if (CI->isOne()) {
+            if (!IndVarIncrement && PN == IndVar)
+              IndVarIncrement = I;
+            // else this is another loop induction variable
+            continue;
+          }
       } else 
         if ((PN = dyn_cast<PHINode>(Op1))) {
           if ((CI = dyn_cast<ConstantInt>(Op0)))
-            IndVarIncrement = I;
+            if (CI->isOne()) {
+              if (!IndVarIncrement && PN == IndVar)
+                IndVarIncrement = I;
+              // else this is another loop induction variable
+              continue;
+            }
       }
-          
-      if (IndVarIncrement && PN == IndVar && CI->isOne())
-        continue;
-    }
+    } 
 
     // I is an Exit condition if next instruction is block terminator.
     // Exit condition is OK if it compares loop invariant exit value,

diff --git a/test/Transforms/LoopIndexSplit/2007-09-25-UpdateIterationSpace-2.ll b/test/Transforms/LoopIndexSplit/2007-09-25-UpdateIterationSpace-2.ll
new file mode 100644 (file)
index 0000000..06f9e11
--- /dev/null
+++ b/test/Transforms/LoopIndexSplit/2007-09-25-UpdateIterationSpace-2.ll
@@ -0,0 +1,59 @@
+; PR714
+; Update loop iteraton space to eliminate condition inside loop.
+; RUN: llvm-as < %s | opt -loop-index-split | llvm-dis | not grep bothcond
+define void @test(float* %x, i32 %ndat, float** %y, float %xcen, i32 %xmin, i32 %xmax, float %sigmal, float %contribution) {
+entry:
+       %tmp5310 = icmp sgt i32 %xmin, %xmax            ; <i1> [#uses=1]
+       br i1 %tmp5310, label %return, label %bb.preheader
+
+bb.preheader:          ; preds = %entry
+       %tmp3031 = fpext float %contribution to double          ; <double> [#uses=1]
+       %tmp32 = mul double %tmp3031, 5.000000e-01              ; <double> [#uses=1]
+       %tmp3839 = fpext float %sigmal to double                ; <double> [#uses=1]
+       br label %bb
+
+bb:            ; preds = %bb.preheader, %cond_next45
+       %i.01.0 = phi i32 [ %tmp47, %cond_next45 ], [ %xmin, %bb.preheader ]            ; <i32> [#uses=4]
+       %k.06.0 = phi i32 [ %tmp49, %cond_next45 ], [ 0, %bb.preheader ]                ; <i32> [#uses=3]
+       %tmp2 = icmp sgt i32 %i.01.0, -1                ; <i1> [#uses=1]
+       %tmp6 = icmp slt i32 %i.01.0, %ndat             ; <i1> [#uses=1]
+       %bothcond = and i1 %tmp2, %tmp6         ; <i1> [#uses=1]
+       br i1 %bothcond, label %cond_true9, label %cond_next45
+
+cond_true9:            ; preds = %bb
+       %tmp12 = getelementptr float* %x, i32 %i.01.0           ; <float*> [#uses=1]
+       %tmp13 = load float* %tmp12, align 4            ; <float> [#uses=1]
+       %tmp15 = sub float %xcen, %tmp13                ; <float> [#uses=1]
+       %tmp16 = tail call float @fabsf( float %tmp15 )         ; <float> [#uses=1]
+       %tmp18 = fdiv float %tmp16, %sigmal             ; <float> [#uses=1]
+       %tmp21 = load float** %y, align 4               ; <float*> [#uses=2]
+       %tmp27 = getelementptr float* %tmp21, i32 %k.06.0               ; <float*> [#uses=1]
+       %tmp28 = load float* %tmp27, align 4            ; <float> [#uses=1]
+       %tmp2829 = fpext float %tmp28 to double         ; <double> [#uses=1]
+       %tmp34 = sub float -0.000000e+00, %tmp18                ; <float> [#uses=1]
+       %tmp3435 = fpext float %tmp34 to double         ; <double> [#uses=1]
+       %tmp36 = tail call double @exp( double %tmp3435 )               ; <double> [#uses=1]
+       %tmp37 = mul double %tmp32, %tmp36              ; <double> [#uses=1]
+       %tmp40 = fdiv double %tmp37, %tmp3839           ; <double> [#uses=1]
+       %tmp41 = add double %tmp2829, %tmp40            ; <double> [#uses=1]
+       %tmp4142 = fptrunc double %tmp41 to float               ; <float> [#uses=1]
+       %tmp44 = getelementptr float* %tmp21, i32 %k.06.0               ; <float*> [#uses=1]
+       store float %tmp4142, float* %tmp44, align 4
+       br label %cond_next45
+
+cond_next45:           ; preds = %bb, %cond_true9
+       %tmp47 = add i32 %i.01.0, 1             ; <i32> [#uses=2]
+       %tmp49 = add i32 %k.06.0, 1             ; <i32> [#uses=1]
+       %tmp53 = icmp sgt i32 %tmp47, %xmax             ; <i1> [#uses=1]
+       br i1 %tmp53, label %return.loopexit, label %bb
+
+return.loopexit:               ; preds = %cond_next45
+       br label %return
+
+return:                ; preds = %return.loopexit, %entry
+       ret void
+}
+
+declare float @fabsf(float)
+
+declare double @exp(double)