[llvm] 721ecc9 - [ConstraintElimination] Transfer info from sgt %a, %b to ugt %a, %b if %b > 0

[Zain Jaffal via llvm-commits]

Author: Zain Jaffal
Date: 2023-04-17T09:27:33+01:00
New Revision: 721ecc9d413c1043c28924bcec700b4dd46ca2f4

URL: https://github.com/llvm/llvm-project/commit/721ecc9d413c1043c28924bcec700b4dd46ca2f4
DIFF: https://github.com/llvm/llvm-project/commit/721ecc9d413c1043c28924bcec700b4dd46ca2f4.diff

LOG: [ConstraintElimination] Transfer info from sgt %a, %b to ugt %a, %b if %b > 0

Differential Revision: https://reviews.llvm.org/D148326

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
    llvm/test/Transforms/ConstraintElimination/gep-sub.ll
    llvm/test/Transforms/ConstraintElimination/signed-query-unsigned-system.ll
    llvm/test/Transforms/ConstraintElimination/transfer-signed-facts-to-unsigned.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
index 762061b1435de..f87839e15a586 100644
--- a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
@@ -582,11 +582,15 @@ void ConstraintInfo::transferToOtherSystem(
     if (doesHold(CmpInst::ICMP_SGE, A, ConstantInt::get(B->getType(), 0)))
       addFact(CmpInst::ICMP_ULT, A, B, NumIn, NumOut, DFSInStack);
     break;
-  case CmpInst::ICMP_SGT:
+  case CmpInst::ICMP_SGT: {
     if (doesHold(CmpInst::ICMP_SGE, B, ConstantInt::get(B->getType(), -1)))
       addFact(CmpInst::ICMP_UGE, A, ConstantInt::get(B->getType(), 0), NumIn,
               NumOut, DFSInStack);
+    if (doesHold(CmpInst::ICMP_SGE, B, ConstantInt::get(B->getType(), 0)))
+      addFact(CmpInst::ICMP_UGT, A, B, NumIn, NumOut, DFSInStack);
+
     break;
+  }
   case CmpInst::ICMP_SGE:
     if (doesHold(CmpInst::ICMP_SGE, B, ConstantInt::get(B->getType(), 0))) {
       addFact(CmpInst::ICMP_UGE, A, B, NumIn, NumOut, DFSInStack);

diff  --git a/llvm/test/Transforms/ConstraintElimination/gep-sub.ll b/llvm/test/Transforms/ConstraintElimination/gep-sub.ll
index b499e280c1e37..3effb6a20d0ca 100644
--- a/llvm/test/Transforms/ConstraintElimination/gep-sub.ll
+++ b/llvm/test/Transforms/ConstraintElimination/gep-sub.ll
@@ -195,7 +195,7 @@ define i1 @gep_sub_ult_var_idx_sgt_1(ptr %dst, ptr %upper, i8 %idx) {
 ; CHECK-NEXT:    [[CMP_SUB_1:%.*]] = icmp ult ptr [[DST_SUB_1]], [[UPPER]]
 ; CHECK-NEXT:    [[DST_SUB_2:%.*]] = getelementptr inbounds i8, ptr [[DST_ADD_IDX]], i64 -2
 ; CHECK-NEXT:    [[CMP_SUB_2:%.*]] = icmp ult ptr [[DST_SUB_2]], [[UPPER]]
-; CHECK-NEXT:    [[RES_1:%.*]] = xor i1 [[CMP_SUB_1]], [[CMP_SUB_2]]
+; CHECK-NEXT:    [[RES_1:%.*]] = xor i1 true, true
 ; CHECK-NEXT:    [[DST_SUB_3:%.*]] = getelementptr inbounds i8, ptr [[DST_ADD_IDX]], i64 -3
 ; CHECK-NEXT:    [[CMP_SUB_3:%.*]] = icmp ult ptr [[DST_SUB_3]], [[UPPER]]
 ; CHECK-NEXT:    [[RES_2:%.*]] = xor i1 [[RES_1]], [[CMP_SUB_3]]

diff  --git a/llvm/test/Transforms/ConstraintElimination/signed-query-unsigned-system.ll b/llvm/test/Transforms/ConstraintElimination/signed-query-unsigned-system.ll
index a78f175541587..104002886bfae 100644
--- a/llvm/test/Transforms/ConstraintElimination/signed-query-unsigned-system.ll
+++ b/llvm/test/Transforms/ConstraintElimination/signed-query-unsigned-system.ll
@@ -39,7 +39,7 @@ define i1 @sgt_0_unsigned_a_sgt_0(i8 %a) {
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[A_SGT_0]])
 ; CHECK-NEXT:    [[EXT:%.*]] = zext i8 [[A]] to i16
 ; CHECK-NEXT:    [[T:%.*]] = icmp sgt i16 [[EXT]], 0
-; CHECK-NEXT:    ret i1 [[T]]
+; CHECK-NEXT:    ret i1 true
 ;
   %a.sgt.0 = icmp sgt i8 %a, 0
   call void @llvm.assume(i1 %a.sgt.0)

diff  --git a/llvm/test/Transforms/ConstraintElimination/transfer-signed-facts-to-unsigned.ll b/llvm/test/Transforms/ConstraintElimination/transfer-signed-facts-to-unsigned.ll
index 6e130aaf32c6d..a2d40ab26c554 100644
--- a/llvm/test/Transforms/ConstraintElimination/transfer-signed-facts-to-unsigned.ll
+++ b/llvm/test/Transforms/ConstraintElimination/transfer-signed-facts-to-unsigned.ll
@@ -580,7 +580,7 @@ define i1 @sgt_known_pos(i8 %idx) {
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
 ; CHECK-NEXT:    [[T_1:%.*]] = icmp ugt i8 [[IDX]], 2
 ; CHECK-NEXT:    [[T_2:%.*]] = icmp ugt i8 [[IDX]], 1
-; CHECK-NEXT:    [[RES_1:%.*]] = xor i1 [[T_1]], [[T_2]]
+; CHECK-NEXT:    [[RES_1:%.*]] = xor i1 true, true
 ; CHECK-NEXT:    [[C_1:%.*]] = icmp ugt i8 [[IDX]], 3
 ; CHECK-NEXT:    [[RES_2:%.*]] = xor i1 [[RES_1]], [[C_1]]
 ; CHECK-NEXT:    ret i1 [[RES_2]]
@@ -602,7 +602,7 @@ define i1 @sgt_to_ugt(i8 %a) {
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[A:%.*]], 2
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
 ; CHECK-NEXT:    [[T_1:%.*]] = icmp ugt i8 [[A]], 2
-; CHECK-NEXT:    ret i1 [[T_1]]
+; CHECK-NEXT:    ret i1 true
 ;
 entry:
   %cmp = icmp sgt i8 %a, 2
@@ -617,7 +617,7 @@ define i1 @sgt_to_ugt_less(i8 %a) {
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[A:%.*]], 2
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
 ; CHECK-NEXT:    [[T_1:%.*]] = icmp ugt i8 [[A]], 1
-; CHECK-NEXT:    ret i1 [[T_1]]
+; CHECK-NEXT:    ret i1 true
 ;
 entry:
   %cmp = icmp sgt i8 %a, 2
@@ -634,7 +634,7 @@ define i1 @sgt_to_ugt_var(i8 %a, i8 %b) {
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP]])
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[CMP_2]])
 ; CHECK-NEXT:    [[T_1:%.*]] = icmp ugt i8 [[A]], [[B]]
-; CHECK-NEXT:    ret i1 [[T_1]]
+; CHECK-NEXT:    ret i1 true
 ;
 entry:
   %cmp = icmp sgt i8 %a, %b