[llvm] 0dda633 - [SCEV] Strength nowrap flags after constant folding
Nikita Popov via llvm-commits
llvm-commits at lists.llvm.org
Sun Oct 25 10:01:02 PDT 2020
Author: Nikita Popov
Date: 2020-10-25T18:00:22+01:00
New Revision: 0dda6333175c1749f12be660456ecedade3bcf21
URL: https://github.com/llvm/llvm-project/commit/0dda6333175c1749f12be660456ecedade3bcf21
DIFF: https://github.com/llvm/llvm-project/commit/0dda6333175c1749f12be660456ecedade3bcf21.diff
LOG: [SCEV] Strength nowrap flags after constant folding
We should first try to constant fold the add expression and only
strengthen nowrap flags afterwards. This allows us to determine
stronger flags if e.g. only two operands are left after constant
folding (and thus "guaranteed no wrap region" code applies) or the
resulting operands are non-negative and thus nsw->nuw strengthening
applies.
Added:
Modified:
llvm/lib/Analysis/ScalarEvolution.cpp
llvm/test/Analysis/ScalarEvolution/ptrtoint-constantexpr-loop.ll
llvm/test/Analysis/ScalarEvolution/trip-count15.ll
llvm/test/Analysis/ScalarEvolution/trip-count9.ll
llvm/test/Transforms/IndVarSimplify/X86/eliminate-trunc.ll
llvm/test/Transforms/IndVarSimplify/X86/pr35406.ll
llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll
llvm/test/Transforms/LoopReroll/nonconst_lb.ll
llvm/test/Transforms/LoopVectorize/X86/load-deref-pred.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index b9edcaf8b16f..e4ed367a6962 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -2178,8 +2178,6 @@ const SCEV *ScalarEvolution::getAddExpr(SmallVectorImpl<const SCEV *> &Ops,
// Sort by complexity, this groups all similar expression types together.
GroupByComplexity(Ops, &LI, DT);
- Flags = StrengthenNoWrapFlags(this, scAddExpr, Ops, Flags);
-
// If there are any constants, fold them together.
unsigned Idx = 0;
if (const SCEVConstant *LHSC = dyn_cast<SCEVConstant>(Ops[0])) {
@@ -2202,6 +2200,8 @@ const SCEV *ScalarEvolution::getAddExpr(SmallVectorImpl<const SCEV *> &Ops,
if (Ops.size() == 1) return Ops[0];
}
+ Flags = StrengthenNoWrapFlags(this, scAddExpr, Ops, Flags);
+
// Limit recursion calls depth.
if (Depth > MaxArithDepth || hasHugeExpression(Ops))
return getOrCreateAddExpr(Ops, Flags);
diff --git a/llvm/test/Analysis/ScalarEvolution/ptrtoint-constantexpr-loop.ll b/llvm/test/Analysis/ScalarEvolution/ptrtoint-constantexpr-loop.ll
index bf8f6340e599..f6364939bb39 100644
--- a/llvm/test/Analysis/ScalarEvolution/ptrtoint-constantexpr-loop.ll
+++ b/llvm/test/Analysis/ScalarEvolution/ptrtoint-constantexpr-loop.ll
@@ -358,9 +358,9 @@ define i64 @sext_like_noop(i32 %n) {
; X32-LABEL: 'sext_like_noop'
; X32-NEXT: Classifying expressions for: @sext_like_noop
; X32-NEXT: %ii = sext i32 %i to i64
-; X32-NEXT: --> (sext i32 {1,+,1}<nuw><%for.body> to i64) U: [-2147483648,2147483648) S: [-2147483648,2147483648) --> (sext i32 (-1 + ptrtoint (i64 (i32)* @sext_like_noop to i32)) to i64) U: [-1,65535) S: [-65537,65535)
+; X32-NEXT: --> (sext i32 {1,+,1}<nuw><%for.body> to i64) U: [-2147483648,2147483648) S: [-2147483648,2147483648) --> (-1 + (sext i32 ptrtoint (i64 (i32)* @sext_like_noop to i32) to i64))<nsw> U: [-1,65535) S: [-65537,65535)
; X32-NEXT: %div = sdiv i64 55555, %ii
-; X32-NEXT: --> %div U: full-set S: full-set --> sdiv (i64 55555, i64 sext (i32 add (i32 ptrtoint (i64 (i32)* @sext_like_noop to i32), i32 -1) to i64)) U: full-set S: full-set
+; X32-NEXT: --> %div U: full-set S: full-set --> sdiv (i64 55555, i64 add (i64 sext (i32 ptrtoint (i64 (i32)* @sext_like_noop to i32) to i64), i64 -1)) U: full-set S: full-set
; X32-NEXT: %i = phi i32 [ %inc, %for.body ], [ 1, %entry ]
; X32-NEXT: --> {1,+,1}<nuw><%for.body> U: [1,0) S: [1,0) Exits: (-1 + ptrtoint (i64 (i32)* @sext_like_noop to i32))<nsw> LoopDispositions: { %for.body: Computable }
; X32-NEXT: %inc = add nuw i32 %i, 1
diff --git a/llvm/test/Analysis/ScalarEvolution/trip-count15.ll b/llvm/test/Analysis/ScalarEvolution/trip-count15.ll
index bfc88452a9cf..600ad9c9161b 100644
--- a/llvm/test/Analysis/ScalarEvolution/trip-count15.ll
+++ b/llvm/test/Analysis/ScalarEvolution/trip-count15.ll
@@ -10,7 +10,7 @@ define void @umin_unsigned_check(i64 %n) {
; CHECK-NEXT: %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
; CHECK-NEXT: --> {0,+,1}<%loop> U: [0,4098) S: [0,4098) Exits: (1 + (4096 umin %n))<nuw><nsw> LoopDispositions: { %loop: Computable }
; CHECK-NEXT: %iv.next = add i64 %iv, 1
-; CHECK-NEXT: --> {1,+,1}<%loop> U: [1,4099) S: [1,4099) Exits: (2 + (4096 umin %n)) LoopDispositions: { %loop: Computable }
+; CHECK-NEXT: --> {1,+,1}<%loop> U: [1,4099) S: [1,4099) Exits: (2 + (4096 umin %n))<nuw><nsw> LoopDispositions: { %loop: Computable }
; CHECK-NEXT: Determining loop execution counts for: @umin_unsigned_check
; CHECK-NEXT: Loop %loop: backedge-taken count is (1 + (4096 umin %n))<nuw><nsw>
; CHECK-NEXT: Loop %loop: max backedge-taken count is 4097
@@ -40,7 +40,7 @@ define void @umin_signed_check(i64 %n) {
; CHECK-NEXT: %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop ]
; CHECK-NEXT: --> {0,+,1}<%loop> U: [0,4098) S: [0,4098) Exits: (1 + (4096 umin %n))<nuw><nsw> LoopDispositions: { %loop: Computable }
; CHECK-NEXT: %iv.next = add i64 %iv, 1
-; CHECK-NEXT: --> {1,+,1}<%loop> U: [1,4099) S: [1,4099) Exits: (2 + (4096 umin %n)) LoopDispositions: { %loop: Computable }
+; CHECK-NEXT: --> {1,+,1}<%loop> U: [1,4099) S: [1,4099) Exits: (2 + (4096 umin %n))<nuw><nsw> LoopDispositions: { %loop: Computable }
; CHECK-NEXT: Determining loop execution counts for: @umin_signed_check
; CHECK-NEXT: Loop %loop: backedge-taken count is (1 + (4096 umin %n))<nuw><nsw>
; CHECK-NEXT: Loop %loop: max backedge-taken count is 4097
diff --git a/llvm/test/Analysis/ScalarEvolution/trip-count9.ll b/llvm/test/Analysis/ScalarEvolution/trip-count9.ll
index 664f9b1296b3..34f7a1a40c58 100644
--- a/llvm/test/Analysis/ScalarEvolution/trip-count9.ll
+++ b/llvm/test/Analysis/ScalarEvolution/trip-count9.ll
@@ -204,9 +204,9 @@ exit:
define void @nsw_start1_step2(i4 %n) {
; CHECK-LABEL: 'nsw_start1_step2'
; CHECK-NEXT: Determining loop execution counts for: @nsw_start1_step2
-; CHECK-NEXT: Loop %loop: backedge-taken count is ((-2 + (3 smax %n)) /u 2)
+; CHECK-NEXT: Loop %loop: backedge-taken count is ((-2 + (3 smax %n))<nsw> /u 2)
; CHECK-NEXT: Loop %loop: max backedge-taken count is 2
-; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is ((-2 + (3 smax %n)) /u 2)
+; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is ((-2 + (3 smax %n))<nsw> /u 2)
; CHECK-NEXT: Predicates:
; CHECK: Loop %loop: Trip multiple is 1
;
@@ -333,9 +333,9 @@ exit:
define void @even_start1_step2(i4 %n) {
; CHECK-LABEL: 'even_start1_step2'
; CHECK-NEXT: Determining loop execution counts for: @even_start1_step2
-; CHECK-NEXT: Loop %loop: backedge-taken count is ((-2 + (3 smax (2 * %n))) /u 2)
+; CHECK-NEXT: Loop %loop: backedge-taken count is ((-2 + (3 smax (2 * %n)))<nsw> /u 2)
; CHECK-NEXT: Loop %loop: max backedge-taken count is 2
-; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is ((-2 + (3 smax (2 * %n))) /u 2)
+; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is ((-2 + (3 smax (2 * %n)))<nsw> /u 2)
; CHECK-NEXT: Predicates:
; CHECK: Loop %loop: Trip multiple is 1
;
@@ -465,9 +465,9 @@ exit:
define void @even_nsw_start1_step2(i4 %n) {
; CHECK-LABEL: 'even_nsw_start1_step2'
; CHECK-NEXT: Determining loop execution counts for: @even_nsw_start1_step2
-; CHECK-NEXT: Loop %loop: backedge-taken count is ((-2 + (3 smax (2 * %n))) /u 2)
+; CHECK-NEXT: Loop %loop: backedge-taken count is ((-2 + (3 smax (2 * %n)))<nsw> /u 2)
; CHECK-NEXT: Loop %loop: max backedge-taken count is 2
-; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is ((-2 + (3 smax (2 * %n))) /u 2)
+; CHECK-NEXT: Loop %loop: Predicated backedge-taken count is ((-2 + (3 smax (2 * %n)))<nsw> /u 2)
; CHECK-NEXT: Predicates:
; CHECK: Loop %loop: Trip multiple is 1
;
diff --git a/llvm/test/Transforms/IndVarSimplify/X86/eliminate-trunc.ll b/llvm/test/Transforms/IndVarSimplify/X86/eliminate-trunc.ll
index 9fb7977c207f..4738369c0aca 100644
--- a/llvm/test/Transforms/IndVarSimplify/X86/eliminate-trunc.ll
+++ b/llvm/test/Transforms/IndVarSimplify/X86/eliminate-trunc.ll
@@ -474,7 +474,7 @@ define void @test_10(i32 %n) {
; CHECK-NEXT: [[TMP1:%.*]] = zext i32 [[TMP0]] to i64
; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i64 [[TMP1]], 90
; CHECK-NEXT: [[UMIN:%.*]] = select i1 [[TMP2]], i64 [[TMP1]], i64 90
-; CHECK-NEXT: [[TMP3:%.*]] = add i64 [[UMIN]], -99
+; CHECK-NEXT: [[TMP3:%.*]] = add nuw nsw i64 [[UMIN]], -99
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ -100, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[LOOP]] ]
diff --git a/llvm/test/Transforms/IndVarSimplify/X86/pr35406.ll b/llvm/test/Transforms/IndVarSimplify/X86/pr35406.ll
index b968c2184803..e51ee24cd343 100644
--- a/llvm/test/Transforms/IndVarSimplify/X86/pr35406.ll
+++ b/llvm/test/Transforms/IndVarSimplify/X86/pr35406.ll
@@ -79,11 +79,9 @@ define i32 @testRem(i8* %p, i64* %p1) {
; CHECK-NEXT: br label [[LOOP1:%.*]]
; CHECK: loop1:
; CHECK-NEXT: [[LOCAL_0_:%.*]] = phi i32 [ 8, [[ENTRY:%.*]] ], [ [[I9:%.*]], [[LOOP2_EXIT:%.*]] ]
-; CHECK-NEXT: [[I:%.*]] = udiv i32 14, [[LOCAL_0_]]
; CHECK-NEXT: [[EXITCOND1:%.*]] = icmp eq i32 [[LOCAL_0_]], 15
; CHECK-NEXT: br i1 [[EXITCOND1]], label [[EXIT:%.*]], label [[GENERAL_CASE24:%.*]]
; CHECK: general_case24:
-; CHECK-NEXT: [[I2:%.*]] = urem i32 60392, [[I]]
; CHECK-NEXT: br i1 false, label [[LOOP2_PREHEADER:%.*]], label [[LOOP2_EXIT]]
; CHECK: loop2.preheader:
; CHECK-NEXT: [[TMP0:%.*]] = udiv i32 14, [[LOCAL_0_]]
@@ -95,15 +93,12 @@ define i32 @testRem(i8* %p, i64* %p1) {
; CHECK-NEXT: br label [[LOOP2:%.*]]
; CHECK: loop2:
; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[TMP5]], [[LOOP2_PREHEADER]] ], [ [[INDVARS_IV_NEXT:%.*]], [[LOOP2]] ]
-; CHECK-NEXT: [[LOCAL_1_56:%.*]] = phi i32 [ [[I3:%.*]], [[LOOP2]] ], [ [[I2]], [[LOOP2_PREHEADER]] ]
; CHECK-NEXT: [[LOCAL_2_57:%.*]] = phi i32 [ [[I7:%.*]], [[LOOP2]] ], [ 1, [[LOOP2_PREHEADER]] ]
-; CHECK-NEXT: [[I3]] = add i32 [[LOCAL_1_56]], -1
+; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nsw i64 [[INDVARS_IV]], -1
; CHECK-NEXT: [[I4:%.*]] = load atomic i64, i64* [[P1:%.*]] unordered, align 8
-; CHECK-NEXT: [[I5:%.*]] = sext i32 [[I3]] to i64
-; CHECK-NEXT: [[I6:%.*]] = sub i64 [[I4]], [[I5]]
+; CHECK-NEXT: [[I6:%.*]] = sub i64 [[I4]], [[INDVARS_IV_NEXT]]
; CHECK-NEXT: store atomic i64 [[I6]], i64* [[P1]] unordered, align 8
; CHECK-NEXT: [[I7]] = add nuw nsw i32 [[LOCAL_2_57]], 1
-; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add i64 [[INDVARS_IV]], -1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp eq i32 [[I7]], 9
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP2_EXIT_LOOPEXIT:%.*]], label [[LOOP2]]
; CHECK: loop2.exit.loopexit:
diff --git a/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll b/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll
index 00e655942c36..addad295153d 100644
--- a/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll
+++ b/llvm/test/Transforms/IndVarSimplify/eliminate-comparison.ll
@@ -577,7 +577,7 @@ define void @func_17(i32* %len.ptr) {
; CHECK: loop.preheader:
; CHECK-NEXT: [[TMP0:%.*]] = icmp sgt i32 [[LEN]], 0
; CHECK-NEXT: [[SMAX:%.*]] = select i1 [[TMP0]], i32 [[LEN]], i32 0
-; CHECK-NEXT: [[TMP1:%.*]] = add i32 [[SMAX]], -5
+; CHECK-NEXT: [[TMP1:%.*]] = add nsw i32 [[SMAX]], -5
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[IV_INC:%.*]], [[BE:%.*]] ], [ -6, [[LOOP_PREHEADER]] ]
diff --git a/llvm/test/Transforms/LoopReroll/nonconst_lb.ll b/llvm/test/Transforms/LoopReroll/nonconst_lb.ll
index 92d893fabbd2..aa5c45636267 100644
--- a/llvm/test/Transforms/LoopReroll/nonconst_lb.ll
+++ b/llvm/test/Transforms/LoopReroll/nonconst_lb.ll
@@ -53,7 +53,7 @@ for.end: ; preds = %for.body, %entry
; CHECK: %1 = sub i32 %0, %m
; CHECK: %2 = lshr i32 %1, 2
; CHECK: %3 = shl nuw i32 %2, 2
-; CHECK: %4 = add i32 %3, 3
+; CHECK: %4 = add nuw nsw i32 %3, 3
; CHECK: br label %for.body
; CHECK: for.body:
@@ -132,7 +132,7 @@ for.end: ; preds = %for.body, %entry
; CHECK: %1 = sub i32 %0, %rem
; CHECK: %2 = lshr i32 %1, 2
; CHECK: %3 = shl nuw i32 %2, 2
-; CHECK: %4 = add i32 %3, 3
+; CHECK: %4 = add nuw nsw i32 %3, 3
; CHECK: br label %for.body
; CHECK: for.body:
diff --git a/llvm/test/Transforms/LoopVectorize/X86/load-deref-pred.ll b/llvm/test/Transforms/LoopVectorize/X86/load-deref-pred.ll
index f4a6f04252f7..97d8b76a1762 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/load-deref-pred.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/load-deref-pred.ll
@@ -841,7 +841,7 @@ define i32 @test_max_trip_count(i64 %len, i1* %test_base, i64 %n) {
; CHECK-NEXT: call void @init(i32* [[BASE]])
; CHECK-NEXT: [[MIN_CMP:%.*]] = icmp ult i64 4096, [[N:%.*]]
; CHECK-NEXT: [[MIN_N:%.*]] = select i1 [[MIN_CMP]], i64 4096, i64 [[N]]
-; CHECK-NEXT: [[TMP0:%.*]] = add i64 [[MIN_N]], 2
+; CHECK-NEXT: [[TMP0:%.*]] = add nuw nsw i64 [[MIN_N]], 2
; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP0]], 16
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
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