InstCombine: move hasOneUse check to the top of foldICmpAddConstant

There were two combines not covered by the check before now, neither of which
actually differed from normal in the benefit analysis.

The most recent seems to be because it was just added at the top of the
function (naturally). The older is from way back in 2008 (r46687) when we just
didn't put those checks in so routinely, and has been diligently maintained
since.

llvm-svn: 341831

6 files changed, 26 insertions, 9 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index e0a1083b927..4b5891461bc 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -2337,6 +2337,9 @@ Instruction *InstCombiner::foldICmpAddConstant(ICmpInst &Cmp,
   Type *Ty = Add->getType();
   CmpInst::Predicate Pred = Cmp.getPredicate();
 
+  if (!Add->hasOneUse())
+    return nullptr;
+
   // If the add does not wrap, we can always adjust the compare by subtracting
   // the constants. Equality comparisons are handled elsewhere. SGE/SLE/UGE/ULE
   // are canonicalized to SGT/SLT/UGT/ULT.
@@ -2370,9 +2373,6 @@ Instruction *InstCombiner::foldICmpAddConstant(ICmpInst &Cmp,
       return new ICmpInst(ICmpInst::ICMP_UGE, X, ConstantInt::get(Ty, Lower));
   }
 
-  if (!Add->hasOneUse())
-    return nullptr;
-
   // X+C <u C2 -> (X & -C2) == C
   //   iff C & (C2-1) == 0
   //       C2 is a power of 2
diff --git a/llvm/test/Analysis/ValueTracking/non-negative-phi-bits.ll b/llvm/test/Analysis/ValueTracking/non-negative-phi-bits.ll
index 3b1c43df5a7..059bbaa3c4e 100755
--- a/llvm/test/Analysis/ValueTracking/non-negative-phi-bits.ll
+++ b/llvm/test/Analysis/ValueTracking/non-negative-phi-bits.ll
@@ -8,7 +8,7 @@ define void @test() #0 {
 ; CHECK:       for.body:
 ; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[INDVARS_IV_NEXT:%.*]], [[FOR_BODY]] ]
 ; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], 1
-; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ult i64 [[INDVARS_IV]], 39
+; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ult i64 [[INDVARS_IV_NEXT]], 40
 ; CHECK-NEXT:    br i1 [[EXITCOND]], label [[FOR_END:%.*]], label [[FOR_BODY]]
 ; CHECK:       for.end:
 ; CHECK-NEXT:    ret void
diff --git a/llvm/test/Transforms/InstCombine/icmp-add.ll b/llvm/test/Transforms/InstCombine/icmp-add.ll
index 901f98c8295..092b69485b0 100644
--- a/llvm/test/Transforms/InstCombine/icmp-add.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-add.ll
@@ -73,6 +73,23 @@ define i1 @test4(i32 %a) {
   ret i1 %c
 }
 
+define { i32, i1 } @test4multiuse(i32 %a) {
+; CHECK-LABEL: @test4multiuse(
+; CHECK: [[B:%.*]] = add i32 %a, -2147483644
+; CHECK: [[C:%.*]] = icmp slt i32 %b, -4
+; CHECK: [[TMP:%.*]] = insertvalue { i32, i1 } undef, i32 [[B]], 0
+; CHECK: [[RES:%.*]] = insertvalue { i32, i1 } [[TMP]], i1 [[C]], 1
+; CHECK: ret { i32, i1 } [[RES]]
+
+  %b = add i32 %a, -2147483644
+  %c = icmp slt i32 %b, -4
+
+  %tmp = insertvalue { i32, i1 } undef, i32 %b, 0
+  %res = insertvalue { i32, i1 } %tmp, i1 %c, 1
+
+  ret { i32, i1 } %res
+}
+
 define <2 x i1> @test4vec(<2 x i32> %a) {
 ; CHECK-LABEL: @test4vec(
 ; CHECK-NEXT:    [[C:%.*]] = icmp slt <2 x i32> %a, <i32 -4, i32 -4>
diff --git a/llvm/test/Transforms/LoopVectorize/X86/masked_load_store.ll b/llvm/test/Transforms/LoopVectorize/X86/masked_load_store.ll
index b3387435f2b..8e948639ba1 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/masked_load_store.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/masked_load_store.ll
@@ -1878,7 +1878,7 @@ define void @foo4(double* %A, double* %B, i32* %trigger)  {
 ; AVX1-NEXT:    br label [[FOR_INC]]
 ; AVX1:       for.inc:
 ; AVX1-NEXT:    [[INDVARS_IV_NEXT:%.*]] = or i64 [[INDVARS_IV]], 16
-; AVX1-NEXT:    [[CMP:%.*]] = icmp ult i64 [[INDVARS_IV]], 9984
+; AVX1-NEXT:    [[CMP:%.*]] = icmp ult i64 [[INDVARS_IV_NEXT]], 10000
 ; AVX1-NEXT:    br i1 [[CMP]], label [[FOR_BODY_1:%.*]], label [[FOR_END:%.*]]
 ; AVX1:       for.end:
 ; AVX1-NEXT:    ret void
@@ -1920,7 +1920,7 @@ define void @foo4(double* %A, double* %B, i32* %trigger)  {
 ; AVX2-NEXT:    br label [[FOR_INC]]
 ; AVX2:       for.inc:
 ; AVX2-NEXT:    [[INDVARS_IV_NEXT:%.*]] = or i64 [[INDVARS_IV]], 16
-; AVX2-NEXT:    [[CMP:%.*]] = icmp ult i64 [[INDVARS_IV]], 9984
+; AVX2-NEXT:    [[CMP:%.*]] = icmp ult i64 [[INDVARS_IV_NEXT]], 10000
 ; AVX2-NEXT:    br i1 [[CMP]], label [[FOR_BODY_1:%.*]], label [[FOR_END:%.*]]
 ; AVX2:       for.end:
 ; AVX2-NEXT:    ret void
@@ -2119,7 +2119,7 @@ define void @foo4(double* %A, double* %B, i32* %trigger)  {
 ; AVX512-NEXT:    br label [[FOR_INC_3]]
 ; AVX512:       for.inc.3:
 ; AVX512-NEXT:    [[INDVARS_IV_NEXT_3]] = add nsw i64 [[INDVARS_IV]], 64
-; AVX512-NEXT:    [[CMP_3:%.*]] = icmp ult i64 [[INDVARS_IV_NEXT_2]], 9984
+; AVX512-NEXT:    [[CMP_3:%.*]] = icmp ult i64 [[INDVARS_IV_NEXT_3]], 10000
 ; AVX512-NEXT:    br i1 [[CMP_3]], label [[FOR_BODY]], label [[FOR_END]], !llvm.loop !52
 ;
 entry:
diff --git a/llvm/test/Transforms/LoopVectorize/if-conversion-nest.ll b/llvm/test/Transforms/LoopVectorize/if-conversion-nest.ll
index 458e350a5e0..311d92b94af 100644
--- a/llvm/test/Transforms/LoopVectorize/if-conversion-nest.ll
+++ b/llvm/test/Transforms/LoopVectorize/if-conversion-nest.ll
@@ -12,7 +12,7 @@ define i32 @foo(i32* nocapture %A, i32* nocapture %B, i32 %n) {
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[N]], -1
 ; CHECK-NEXT:    [[TMP1:%.*]] = zext i32 [[TMP0]] to i64
 ; CHECK-NEXT:    [[TMP2:%.*]] = add nuw nsw i64 [[TMP1]], 1
-; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i32 [[TMP0]], 3
+; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP2]], 4
 ; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_MEMCHECK:%.*]]
 ; CHECK:       vector.memcheck:
 ; CHECK-NEXT:    [[TMP3:%.*]] = add i32 [[N]], -1
diff --git a/llvm/test/Transforms/LoopVectorize/runtime-check.ll b/llvm/test/Transforms/LoopVectorize/runtime-check.ll
index de43a613c09..88489faa831 100644
--- a/llvm/test/Transforms/LoopVectorize/runtime-check.ll
+++ b/llvm/test/Transforms/LoopVectorize/runtime-check.ll
@@ -18,7 +18,7 @@ define i32 @foo(float* nocapture %a, float* nocapture %b, i32 %n) nounwind uwtab
 ; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[N]], -1, !dbg !9
 ; CHECK-NEXT:    [[TMP1:%.*]] = zext i32 [[TMP0]] to i64, !dbg !9
 ; CHECK-NEXT:    [[TMP2:%.*]] = add nuw nsw i64 [[TMP1]], 1, !dbg !9
-; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i32 [[TMP0]], 3, !dbg !9
+; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP2]], 4, !dbg !9
 ; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_MEMCHECK:%.*]], !dbg !9
 ; CHECK:       vector.memcheck:
 ; CHECK-NEXT:    [[TMP3:%.*]] = add i32 [[N]], -1, !dbg !9