[polly] r308608 - [ScopInfo] Add support for wrap-around of integers in unsigned comparisons.
Michael Kruse via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 20 05:37:02 PDT 2017
Author: meinersbur
Date: Thu Jul 20 05:37:02 2017
New Revision: 308608
URL: http://llvm.org/viewvc/llvm-project?rev=308608&view=rev
Log:
[ScopInfo] Add support for wrap-around of integers in unsigned comparisons.
This is one possible solution to implement wrap-arounds for integers in
unsigned icmp operations. For example,
store i32 -1, i32* %A_addr
%0 = load i32, i32* %A_addr
%1 = icmp ult i32 %0, 0
%1 should hold false, because under the assumption of unsigned integers,
-1 should wrap around to 2^32-1. However, previously. it was assumed
that the MSB (Most Significant Bit - aka the Sign bit) was never set for
integers in unsigned operations.
This patch modifies the buildConditionSets function in ScopInfo.cpp to
give better information about the integers in these unsigned
comparisons.
Contributed-by: Annanay Agarwal <cs14btech11001 at iith.ac.in>
Differential Revision: https://reviews.llvm.org/D35464
Added:
polly/trunk/test/ScopInfo/unsigned_wrap_uge.ll
polly/trunk/test/ScopInfo/unsigned_wrap_ugt.ll
polly/trunk/test/ScopInfo/unsigned_wrap_ule.ll
polly/trunk/test/ScopInfo/unsigned_wrap_ult.ll
Modified:
polly/trunk/lib/Analysis/ScopInfo.cpp
polly/trunk/test/ScopInfo/simple_loop_unsigned.ll
polly/trunk/test/ScopInfo/simple_loop_unsigned_3.ll
polly/trunk/test/ScopInfo/zero_ext_of_truncate.ll
polly/trunk/test/ScopInfo/zero_ext_of_truncate_2.ll
Modified: polly/trunk/lib/Analysis/ScopInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/Analysis/ScopInfo.cpp?rev=308608&r1=308607&r2=308608&view=diff
==============================================================================
--- polly/trunk/lib/Analysis/ScopInfo.cpp (original)
+++ polly/trunk/lib/Analysis/ScopInfo.cpp Thu Jul 20 05:37:02 2017
@@ -1536,6 +1536,47 @@ buildConditionSets(Scop &S, BasicBlock *
return true;
}
+/// Build condition sets for unsigned ICmpInst(s).
+/// Special handling is required for unsigned operands to ensure that if
+/// MSB (aka the Sign bit) is set for an operands in an unsigned ICmpInst
+/// it should wrap around.
+///
+/// @param IsStrictUpperBound holds information on the predicate relation
+/// between TestVal and UpperBound, i.e,
+/// TestVal < UpperBound OR TestVal <= UpperBound
+static __isl_give isl_set *
+buildUnsignedConditionSets(Scop &S, BasicBlock *BB, Value *Condition,
+ __isl_keep isl_set *Domain, const SCEV *SCEV_TestVal,
+ const SCEV *SCEV_UpperBound,
+ DenseMap<BasicBlock *, isl::set> &InvalidDomainMap,
+ bool IsStrictUpperBound) {
+
+ // Do not take NonNeg assumption on TestVal
+ // as it might have MSB (Sign bit) set.
+ isl_pw_aff *TestVal = getPwAff(S, BB, InvalidDomainMap, SCEV_TestVal, false);
+ // Take NonNeg assumption on UpperBound.
+ isl_pw_aff *UpperBound =
+ getPwAff(S, BB, InvalidDomainMap, SCEV_UpperBound, true);
+
+ // 0 <= TestVal
+ isl_set *First =
+ isl_pw_aff_le_set(isl_pw_aff_zero_on_domain(isl_local_space_from_space(
+ isl_pw_aff_get_domain_space(TestVal))),
+ isl_pw_aff_copy(TestVal));
+
+ isl_set *Second;
+ if (IsStrictUpperBound)
+ // TestVal < UpperBound
+ Second = isl_pw_aff_lt_set(TestVal, UpperBound);
+ else
+ // TestVal <= UpperBound
+ Second = isl_pw_aff_le_set(TestVal, UpperBound);
+
+ isl_set *ConsequenceCondSet = isl_set_intersect(First, Second);
+ ConsequenceCondSet = setDimensionIds(Domain, ConsequenceCondSet);
+ return ConsequenceCondSet;
+}
+
/// Build the conditions sets for the branch condition @p Condition in
/// the @p Domain.
///
@@ -1590,12 +1631,37 @@ buildConditionSets(Scop &S, BasicBlock *
// to be set. The comparison is equal to a signed comparison under this
// assumption.
bool NonNeg = ICond->isUnsigned();
- LHS = getPwAff(S, BB, InvalidDomainMap,
- SE.getSCEVAtScope(ICond->getOperand(0), L), NonNeg);
- RHS = getPwAff(S, BB, InvalidDomainMap,
- SE.getSCEVAtScope(ICond->getOperand(1), L), NonNeg);
- ConsequenceCondSet =
- buildConditionSet(ICond->getPredicate(), LHS, RHS, Domain);
+ const SCEV *LeftOperand = SE.getSCEVAtScope(ICond->getOperand(0), L),
+ *RightOperand = SE.getSCEVAtScope(ICond->getOperand(1), L);
+
+ switch (ICond->getPredicate()) {
+ case ICmpInst::ICMP_ULT:
+ ConsequenceCondSet =
+ buildUnsignedConditionSets(S, BB, Condition, Domain, LeftOperand,
+ RightOperand, InvalidDomainMap, true);
+ break;
+ case ICmpInst::ICMP_ULE:
+ ConsequenceCondSet =
+ buildUnsignedConditionSets(S, BB, Condition, Domain, LeftOperand,
+ RightOperand, InvalidDomainMap, false);
+ break;
+ case ICmpInst::ICMP_UGT:
+ ConsequenceCondSet =
+ buildUnsignedConditionSets(S, BB, Condition, Domain, RightOperand,
+ LeftOperand, InvalidDomainMap, true);
+ break;
+ case ICmpInst::ICMP_UGE:
+ ConsequenceCondSet =
+ buildUnsignedConditionSets(S, BB, Condition, Domain, RightOperand,
+ LeftOperand, InvalidDomainMap, false);
+ break;
+ default:
+ LHS = getPwAff(S, BB, InvalidDomainMap, LeftOperand, NonNeg);
+ RHS = getPwAff(S, BB, InvalidDomainMap, RightOperand, NonNeg);
+ ConsequenceCondSet =
+ buildConditionSet(ICond->getPredicate(), LHS, RHS, Domain);
+ break;
+ }
}
// If no terminator was given we are only looking for parameter constraints
Modified: polly/trunk/test/ScopInfo/simple_loop_unsigned.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/simple_loop_unsigned.ll?rev=308608&r1=308607&r2=308608&view=diff
==============================================================================
--- polly/trunk/test/ScopInfo/simple_loop_unsigned.ll (original)
+++ polly/trunk/test/ScopInfo/simple_loop_unsigned.ll Thu Jul 20 05:37:02 2017
@@ -10,10 +10,10 @@
; CHECK: Assumed Context:
; CHECK-NEXT: [N] -> { : }
; CHECK-NEXT: Invalid Context:
-; CHECK-NEXT: [N] -> { : N < 0 }
+; CHECK-NEXT: [N] -> { : 1 = 0 }
;
; CHECK: Domain :=
-; CHECK-NEXT: [N] -> { Stmt_bb[i0] : 0 <= i0 < N; Stmt_bb[0] : N <= 0 };
+; CHECK-NEXT: [N] -> { Stmt_bb[i0] : 0 <= i0 < N; Stmt_bb[0] : N = 0 };
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
Modified: polly/trunk/test/ScopInfo/simple_loop_unsigned_3.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/simple_loop_unsigned_3.ll?rev=308608&r1=308607&r2=308608&view=diff
==============================================================================
--- polly/trunk/test/ScopInfo/simple_loop_unsigned_3.ll (original)
+++ polly/trunk/test/ScopInfo/simple_loop_unsigned_3.ll Thu Jul 20 05:37:02 2017
@@ -4,7 +4,7 @@
; CHECK-NEXT: [N] -> { : }
;
; CHECK: Domain :=
-; CHECK-NEXT: [N] -> { Stmt_bb[i0] : 0 < i0 <= 1000 - N; Stmt_bb[0] };
+; CHECK-NEXT: [N] -> { Stmt_bb[0] };
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
Added: polly/trunk/test/ScopInfo/unsigned_wrap_uge.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/unsigned_wrap_uge.ll?rev=308608&view=auto
==============================================================================
--- polly/trunk/test/ScopInfo/unsigned_wrap_uge.ll (added)
+++ polly/trunk/test/ScopInfo/unsigned_wrap_uge.ll Thu Jul 20 05:37:02 2017
@@ -0,0 +1,46 @@
+; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
+;
+; Unsigned wrap-around check.
+;
+; for (int i = -1; i < 65 ; i ++ )
+; if ( 63 >= (unsigned)i )
+; A[i] = 42;
+
+
+define void @func(double* noalias nonnull %A) {
+entry:
+ br label %for
+
+ for:
+ %j = phi i32 [-1, %entry], [%j.inc, %inc]
+ %j.cmp = icmp slt i32 %j, 65
+ br i1 %j.cmp, label %body, label %exit
+
+ body:
+ %inbounds = icmp uge i32 63, %j
+ br i1 %inbounds, label %ifinbounds, label %ifoutbounds
+
+ ifinbounds:
+ %A_idx = getelementptr inbounds double, double* %A, i32 %j
+ store double 42.0, double* %A_idx
+ br label %inc
+
+ ifoutbounds:
+ br label %inc
+
+ inc:
+ %j.inc = add nuw nsw i32 %j, 1
+ br label %for
+
+ exit:
+ br label %return
+
+ return:
+ ret void
+}
+
+
+; CHECK: Region: %for---%return
+; CHECK: Domain :=
+; CHECK-NEXT: { Stmt_ifinbounds[i0] : 0 < i0 <= 64 };
+
Added: polly/trunk/test/ScopInfo/unsigned_wrap_ugt.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/unsigned_wrap_ugt.ll?rev=308608&view=auto
==============================================================================
--- polly/trunk/test/ScopInfo/unsigned_wrap_ugt.ll (added)
+++ polly/trunk/test/ScopInfo/unsigned_wrap_ugt.ll Thu Jul 20 05:37:02 2017
@@ -0,0 +1,46 @@
+; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
+;
+; Unsigned wrap-around check.
+;
+; for (int i = -1; i < 65 ; i ++ )
+; if ( 64 > (unsigned)i )
+; A[i] = 42;
+
+
+define void @func(double* noalias nonnull %A) {
+entry:
+ br label %for
+
+ for:
+ %j = phi i32 [-1, %entry], [%j.inc, %inc]
+ %j.cmp = icmp slt i32 %j, 65
+ br i1 %j.cmp, label %body, label %exit
+
+ body:
+ %inbounds = icmp ugt i32 64, %j
+ br i1 %inbounds, label %ifinbounds, label %ifoutbounds
+
+ ifinbounds:
+ %A_idx = getelementptr inbounds double, double* %A, i32 %j
+ store double 42.0, double* %A_idx
+ br label %inc
+
+ ifoutbounds:
+ br label %inc
+
+ inc:
+ %j.inc = add nuw nsw i32 %j, 1
+ br label %for
+
+ exit:
+ br label %return
+
+ return:
+ ret void
+}
+
+
+; CHECK: Region: %for---%return
+; CHECK: Domain :=
+; CHECK-NEXT: { Stmt_ifinbounds[i0] : 0 < i0 <= 64 };
+
Added: polly/trunk/test/ScopInfo/unsigned_wrap_ule.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/unsigned_wrap_ule.ll?rev=308608&view=auto
==============================================================================
--- polly/trunk/test/ScopInfo/unsigned_wrap_ule.ll (added)
+++ polly/trunk/test/ScopInfo/unsigned_wrap_ule.ll Thu Jul 20 05:37:02 2017
@@ -0,0 +1,46 @@
+; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
+;
+; Unsigned wrap-around check.
+;
+; for (int i = -1; i < 65 ; i ++ )
+; if ( (unsigned)i <= 63 )
+; A[i] = 42;
+
+
+define void @func(double* noalias nonnull %A) {
+entry:
+ br label %for
+
+ for:
+ %j = phi i32 [-1, %entry], [%j.inc, %inc]
+ %j.cmp = icmp slt i32 %j, 65
+ br i1 %j.cmp, label %body, label %exit
+
+ body:
+ %inbounds = icmp ule i32 %j, 63
+ br i1 %inbounds, label %ifinbounds, label %ifoutbounds
+
+ ifinbounds:
+ %A_idx = getelementptr inbounds double, double* %A, i32 %j
+ store double 42.0, double* %A_idx
+ br label %inc
+
+ ifoutbounds:
+ br label %inc
+
+ inc:
+ %j.inc = add nuw nsw i32 %j, 1
+ br label %for
+
+ exit:
+ br label %return
+
+ return:
+ ret void
+}
+
+
+; CHECK: Region: %for---%return
+; CHECK: Domain :=
+; CHECK-NEXT: { Stmt_ifinbounds[i0] : 0 < i0 <= 64 };
+
Added: polly/trunk/test/ScopInfo/unsigned_wrap_ult.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/unsigned_wrap_ult.ll?rev=308608&view=auto
==============================================================================
--- polly/trunk/test/ScopInfo/unsigned_wrap_ult.ll (added)
+++ polly/trunk/test/ScopInfo/unsigned_wrap_ult.ll Thu Jul 20 05:37:02 2017
@@ -0,0 +1,46 @@
+; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
+;
+; Unsigned wrap-around check.
+;
+; for (int i = -1; i < 65 ; i ++ )
+; if ( (unsigned)i < 64 )
+; A[i] = 42;
+
+
+define void @func(double* noalias nonnull %A) {
+entry:
+ br label %for
+
+ for:
+ %j = phi i32 [-1, %entry], [%j.inc, %inc]
+ %j.cmp = icmp slt i32 %j, 65
+ br i1 %j.cmp, label %body, label %exit
+
+ body:
+ %inbounds = icmp ult i32 %j, 64
+ br i1 %inbounds, label %ifinbounds, label %ifoutbounds
+
+ ifinbounds:
+ %A_idx = getelementptr inbounds double, double* %A, i32 %j
+ store double 42.0, double* %A_idx
+ br label %inc
+
+ ifoutbounds:
+ br label %inc
+
+ inc:
+ %j.inc = add nuw nsw i32 %j, 1
+ br label %for
+
+ exit:
+ br label %return
+
+ return:
+ ret void
+}
+
+
+; CHECK: Region: %for---%return
+; CHECK: Domain :=
+; CHECK-NEXT: { Stmt_ifinbounds[i0] : 0 < i0 <= 64 };
+
Modified: polly/trunk/test/ScopInfo/zero_ext_of_truncate.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/zero_ext_of_truncate.ll?rev=308608&r1=308607&r2=308608&view=diff
==============================================================================
--- polly/trunk/test/ScopInfo/zero_ext_of_truncate.ll (original)
+++ polly/trunk/test/ScopInfo/zero_ext_of_truncate.ll Thu Jul 20 05:37:02 2017
@@ -16,7 +16,7 @@
; CHECK-NEXT: [N, tmp, M] -> { : N < 0 or (N > 0 and tmp >= 128) or (N > 0 and tmp < 0) or (N > 0 and M < 0) }
;
; CHECK: Domain :=
-; CHECK-NEXT: [N, tmp, M] -> { Stmt_if_then[i0] : M > tmp and 0 <= i0 < N };
+; CHECK-NEXT: [N, tmp, M] -> { Stmt_if_then[i0] : tmp >= 0 and M > tmp and 0 <= i0 < N };
;
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
Modified: polly/trunk/test/ScopInfo/zero_ext_of_truncate_2.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/zero_ext_of_truncate_2.ll?rev=308608&r1=308607&r2=308608&view=diff
==============================================================================
--- polly/trunk/test/ScopInfo/zero_ext_of_truncate_2.ll (original)
+++ polly/trunk/test/ScopInfo/zero_ext_of_truncate_2.ll Thu Jul 20 05:37:02 2017
@@ -15,7 +15,7 @@
; CHECK-NEXT: [N, tmp] -> { : N > 0 and (tmp < 0 or tmp >= 2147483648) }
;
; CHECK: Domain :=
-; CHECK-NEXT: [N, tmp] -> { Stmt_if_then[i0] : i0 > tmp and 0 <= i0 < N };
+; CHECK-NEXT: [N, tmp] -> { Stmt_if_then[i0] : tmp >= 0 and tmp < i0 < N };
;
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
More information about the llvm-commits
mailing list