[llvm] d0f1f5a - [StackSafety] Use getSignedRange for offsets

[Vitaly Buka via llvm-commits]

Author: Vitaly Buka
Date: 2020-05-26T23:22:36-07:00
New Revision: d0f1f5adfa574ece80d566f400ebb689ae822a16

URL: https://github.com/llvm/llvm-project/commit/d0f1f5adfa574ece80d566f400ebb689ae822a16
DIFF: https://github.com/llvm/llvm-project/commit/d0f1f5adfa574ece80d566f400ebb689ae822a16.diff

LOG: [StackSafety] Use getSignedRange for offsets

Added: 
    

Modified: 
    llvm/lib/Analysis/StackSafetyAnalysis.cpp
    llvm/test/Analysis/StackSafetyAnalysis/ipa.ll
    llvm/test/Analysis/StackSafetyAnalysis/local.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/StackSafetyAnalysis.cpp b/llvm/lib/Analysis/StackSafetyAnalysis.cpp
index 10b9f14bc75a..f72197e827a2 100644
--- a/llvm/lib/Analysis/StackSafetyAnalysis.cpp
+++ b/llvm/lib/Analysis/StackSafetyAnalysis.cpp
@@ -226,10 +226,10 @@ ConstantRange StackSafetyLocalAnalysis::offsetFrom(Value *Addr, Value *Base) {
 
   AllocaOffsetRewriter Rewriter(SE, Base);
   const SCEV *Expr = Rewriter.visit(SE.getSCEV(Addr));
-  ConstantRange Offset = SE.getUnsignedRange(Expr).zextOrTrunc(PointerSize);
-  if (Offset.isEmptySet())
+  ConstantRange Offset = SE.getSignedRange(Expr);
+  if (Offset.isEmptySet() || Offset.isFullSet() || Offset.isSignWrappedSet())
     return UnknownRange;
-  return Offset;
+  return Offset.sextOrTrunc(PointerSize);
 }
 
 ConstantRange

diff  --git a/llvm/test/Analysis/StackSafetyAnalysis/ipa.ll b/llvm/test/Analysis/StackSafetyAnalysis/ipa.ll
index 6791dd0866b8..fe378d355adc 100644
--- a/llvm/test/Analysis/StackSafetyAnalysis/ipa.ll
+++ b/llvm/test/Analysis/StackSafetyAnalysis/ipa.ll
@@ -434,14 +434,14 @@ entry:
 ; CHECK-NEXT: args uses:
 ; LOCAL-NEXT: p[]: [0,4), @RecursiveNoOffset(arg0, [4,5)){{$}}
 ; GLOBAL-NEXT: p[]: full-set, @RecursiveNoOffset(arg0, [4,5)){{$}}
-; CHECK-NEXT: size[]: empty-set, @RecursiveNoOffset(arg1, [4294967295,4294967296)){{$}}
+; CHECK-NEXT: size[]: empty-set, @RecursiveNoOffset(arg1, [-1,0)){{$}}
 ; CHECK-NEXT: acc[]: [0,4), @RecursiveNoOffset(arg2, [0,1)){{$}}
 ; CHECK-NEXT: allocas uses:
 ; CHECK-NOT: ]:
 
 ; CHECK-LABEL: @RecursiveWithOffset{{$}}
 ; CHECK-NEXT: args uses:
-; CHECK-NEXT: size[]: empty-set, @RecursiveWithOffset(arg0, [4294967295,4294967296)){{$}}
+; CHECK-NEXT: size[]: empty-set, @RecursiveWithOffset(arg0, [-1,0)){{$}}
 ; LOCAL-NEXT: acc[]: [0,4), @RecursiveWithOffset(arg1, [4,5)){{$}}
 ; GLOBAL-NEXT: acc[]: full-set, @RecursiveWithOffset(arg1, [4,5)){{$}}
 ; CHECK-NEXT: allocas uses:

diff  --git a/llvm/test/Analysis/StackSafetyAnalysis/local.ll b/llvm/test/Analysis/StackSafetyAnalysis/local.ll
index b7c9eb1d2953..445fb5c46a90 100644
--- a/llvm/test/Analysis/StackSafetyAnalysis/local.ll
+++ b/llvm/test/Analysis/StackSafetyAnalysis/local.ll
@@ -70,7 +70,7 @@ define void @StoreInBounds4() {
 ; CHECK-LABEL: @StoreInBounds4 dso_preemptable{{$}}
 ; CHECK-NEXT: args uses:
 ; CHECK-NEXT: allocas uses:
-; CHECK-NEXT: x[4]: [2,-1){{$}}
+; CHECK-NEXT: x[4]: [-9223372036854775808,9223372036854775807){{$}}
 ; CHECK-NOT: ]:
 entry:
   %x = alloca i32, align 4
@@ -178,7 +178,7 @@ define void @NonConstantOffset(i1 zeroext %z) {
 ; CHECK-NEXT: z[]: full-set{{$}}
 ; CHECK-NEXT: allocas uses:
 ; FIXME: SCEV can't look through selects.
-; CHECK-NEXT: x[4]: [0,4){{$}}
+; CHECK-NEXT: x[4]: [-4,4){{$}}
 ; CHECK-NOT: ]:
 entry:
   %x = alloca i32, align 4
@@ -189,12 +189,39 @@ entry:
   ret void
 }
 
+define void @NegativeOffset() {
+; CHECK-LABEL: @NegativeOffset dso_preemptable{{$}}
+; CHECK-NEXT: args uses:
+; CHECK-NEXT: allocas uses:
+; CHECK-NEXT: x[40]: [-1600000000000,-1599999999996){{$}}
+; CHECK-NOT: ]:
+entry:
+  %x = alloca i32, i32 10, align 4
+  %x2 = getelementptr i32, i32* %x, i64 -400000000000
+  store i32 0, i32* %x2, align 1
+  ret void
+}
+
+define void @PossiblyNegativeOffset(i16 %z) {
+; CHECK-LABEL: @PossiblyNegativeOffset dso_preemptable{{$}}
+; CHECK-NEXT: args uses:
+; CHECK-NEXT: z[]: full-set
+; CHECK-NEXT: allocas uses:
+; CHECK-NEXT: x[40]: [-131072,131072){{$}}
+; CHECK-NOT: ]:
+entry:
+  %x = alloca i32, i32 10, align 4
+  %x2 = getelementptr i32, i32* %x, i16 %z
+  store i32 0, i32* %x2, align 1
+  ret void
+}
+
 define void @NonConstantOffsetOOB(i1 zeroext %z) {
 ; CHECK-LABEL: @NonConstantOffsetOOB dso_preemptable{{$}}
 ; CHECK-NEXT: args uses:
 ; CHECK-NEXT: z[]: full-set{{$}}
 ; CHECK-NEXT: allocas uses:
-; CHECK-NEXT: x[4]: [0,6){{$}}
+; CHECK-NEXT: x[4]: [-8,8){{$}}
 ; CHECK-NOT: ]:
 entry:
   %x = alloca i32, align 4
@@ -251,7 +278,7 @@ entry:
 define void @DynamicAlloca(i64 %size) {
 ; CHECK-LABEL: @DynamicAlloca dso_preemptable{{$}}
 ; CHECK-NEXT: args uses:
-; CHECK-NEXT: size[]: [0,-12){{$}}
+; CHECK-NEXT: size[]: [-9223372036854775808,9223372036854775796){{$}}
 ; CHECK-NEXT: allocas uses:
 ; CHECK-NEXT: x[0]: [0,4){{$}}
 ; CHECK-NOT: ]:
@@ -266,7 +293,7 @@ entry:
 define void @DynamicAllocaFiniteSizeRange(i1 zeroext %z) {
 ; CHECK-LABEL: @DynamicAllocaFiniteSizeRange dso_preemptable{{$}}
 ; CHECK-NEXT: args uses:
-; CHECK-NEXT: z[]: [0,-12){{$}}
+; CHECK-NEXT: z[]: [-9223372036854775808,9223372036854775796){{$}}
 ; CHECK-NEXT: allocas uses:
 ; CHECK-NEXT: x[0]: [0,4){{$}}
 ; CHECK-NOT: ]: