Revert "[SimplifyCFG] Improve the precision of `PtrValueMayBeModified`"

This reverts commit f890f010f6a70addbd885acd0c8d1b9578b6246f.

diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 28a09e8..9824cb3 100644 (file)
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -7110,16 +7110,7 @@ static bool passingValueIsAlwaysUndefined(Value *V, Instruction *I, bool PtrValu
     // Look through GEPs. A load from a GEP derived from NULL is still undefined
     if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Use))
       if (GEP->getPointerOperand() == I) {
-        // The current base address is null, there are four cases to consider:
-        // getelementptr (TY, null, 0)                 -> null
-        // getelementptr (TY, null, not zero)          -> may be modified
-        // getelementptr inbounds (TY, null, 0)        -> null
-        // getelementptr inbounds (TY, null, not zero) -> poison iff null is
-        // undefined?
-        if (!GEP->hasAllZeroIndices() &&
-            (!GEP->isInBounds() ||
-             NullPointerIsDefined(GEP->getFunction(),
-                                  GEP->getPointerAddressSpace())))
+        if (!GEP->isInBounds() || !GEP->hasAllZeroIndices())
           PtrValueMayBeModified = true;
         return passingValueIsAlwaysUndefined(V, GEP, PtrValueMayBeModified);
       }

diff --git a/llvm/test/Transforms/SimplifyCFG/UnreachableEliminate.ll b/llvm/test/Transforms/SimplifyCFG/UnreachableEliminate.ll
index 1dee070..7fe32df 100644 (file)
--- a/llvm/test/Transforms/SimplifyCFG/UnreachableEliminate.ll
+++ b/llvm/test/Transforms/SimplifyCFG/UnreachableEliminate.ll
@@ -444,28 +444,6 @@ else:
 define void @test9_gep_inbounds_nonzero(i1 %X, ptr %Y) {
 ; CHECK-LABEL: @test9_gep_inbounds_nonzero(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[TMP0:%.*]] = xor i1 [[X:%.*]], true
-; CHECK-NEXT:    call void @llvm.assume(i1 [[TMP0]])
-; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds i8, ptr [[Y:%.*]], i64 12
-; CHECK-NEXT:    [[TMP1:%.*]] = call ptr @fn_nonnull_noundef_arg(ptr [[GEP]])
-; CHECK-NEXT:    ret void
-;
-entry:
-  br i1 %X, label %if, label %else
-
-if:
-  br label %else
-
-else:
-  %phi = phi ptr [ %Y, %entry ], [ null, %if ]
-  %gep = getelementptr inbounds i8, ptr %phi, i64 12
-  call ptr @fn_nonnull_noundef_arg(ptr %gep)
-  ret void
-}
-
-define void @test9_gep_inbounds_nonzero_null_defined(i1 %X, ptr %Y) #0 {
-; CHECK-LABEL: @test9_gep_inbounds_nonzero_null_defined(
-; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[SPEC_SELECT:%.*]] = select i1 [[X:%.*]], ptr null, ptr [[Y:%.*]]
 ; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds i8, ptr [[SPEC_SELECT]], i64 12
 ; CHECK-NEXT:    [[TMP0:%.*]] = call ptr @fn_nonnull_noundef_arg(ptr [[GEP]])
@@ -484,30 +462,9 @@ else:
   ret void
 }
 
-define void @test9_gep_inbounds_unknown_null(i1 %X, ptr %Y, i64 %I) {
-; CHECK-LABEL: @test9_gep_inbounds_unknown_null(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[TMP0:%.*]] = xor i1 [[X:%.*]], true
-; CHECK-NEXT:    call void @llvm.assume(i1 [[TMP0]])
-; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds i8, ptr [[Y:%.*]], i64 [[I:%.*]]
-; CHECK-NEXT:    [[TMP1:%.*]] = call ptr @fn_nonnull_noundef_arg(ptr [[GEP]])
-; CHECK-NEXT:    ret void
-;
-entry:
-  br i1 %X, label %if, label %else
-
-if:
-  br label %else
-
-else:
-  %phi = phi ptr [ %Y, %entry ], [ null, %if ]
-  %gep = getelementptr inbounds i8, ptr %phi, i64 %I
-  call ptr @fn_nonnull_noundef_arg(ptr %gep)
-  ret void
-}
 
-define void @test9_gep_inbounds_unknown_null_defined(i1 %X, ptr %Y, i64 %I) #0 {
-; CHECK-LABEL: @test9_gep_inbounds_unknown_null_defined(
+define void @test9_gep_inbouds_unknown_null(i1 %X, ptr %Y, i64 %I) {
+; CHECK-LABEL: @test9_gep_inbouds_unknown_null(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[SPEC_SELECT:%.*]] = select i1 [[X:%.*]], ptr null, ptr [[Y:%.*]]
 ; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds i8, ptr [[SPEC_SELECT]], i64 [[I:%.*]]
@@ -527,27 +484,6 @@ else:
   ret void
 }
 
-define void @test9_gep_inbounds_unknown_null_call_noundef(i1 %X, ptr %Y, i64 %I) {
-; CHECK-LABEL: @test9_gep_inbounds_unknown_null_call_noundef(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[SPEC_SELECT:%.*]] = select i1 [[X:%.*]], ptr null, ptr [[Y:%.*]]
-; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds i8, ptr [[SPEC_SELECT]], i64 [[I:%.*]]
-; CHECK-NEXT:    [[TMP0:%.*]] = call ptr @fn_noundef_arg(ptr [[GEP]])
-; CHECK-NEXT:    ret void
-;
-entry:
-  br i1 %X, label %if, label %else
-
-if:
-  br label %else
-
-else:
-  %phi = phi ptr [ %Y, %entry ], [ null, %if ]
-  %gep = getelementptr inbounds i8, ptr %phi, i64 %I
-  call ptr @fn_noundef_arg(ptr %gep)
-  ret void
-}
-
 define void @test9_gep_unknown_null(i1 %X, ptr %Y, i64 %I) {
 ; CHECK-LABEL: @test9_gep_unknown_null(
 ; CHECK-NEXT:  entry:

diff --git a/llvm/test/Transforms/SimplifyCFG/unreachable-eliminate-on-ret.ll b/llvm/test/Transforms/SimplifyCFG/unreachable-eliminate-on-ret.ll
index 924f98a..e250a5d 100644 (file)
--- a/llvm/test/Transforms/SimplifyCFG/unreachable-eliminate-on-ret.ll
+++ b/llvm/test/Transforms/SimplifyCFG/unreachable-eliminate-on-ret.ll
@@ -55,26 +55,7 @@ define nonnull noundef ptr @test_ret_ptr_nonnull_noundef_gep_nonzero(i1 %cond, p
 ; CHECK-LABEL: @test_ret_ptr_nonnull_noundef_gep_nonzero(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[SPEC_SELECT:%.*]] = select i1 [[COND:%.*]], ptr [[X:%.*]], ptr null
-; CHECK-NEXT:    [[GEP:%.*]] = getelementptr ptr, ptr [[SPEC_SELECT]], i64 12
-; CHECK-NEXT:    ret ptr [[GEP]]
-;
-entry:
-  br i1 %cond, label %bb1, label %bb2
-
-bb1:
-  br label %bb2
-
-bb2:
-  %phi = phi ptr [ null, %entry ], [ %x, %bb1 ]
-  %gep = getelementptr ptr, ptr %phi, i64 12
-  ret ptr %gep
-}
-
-define nonnull noundef ptr @test_ret_ptr_nonnull_noundef_gep_inbounds_nonzero(i1 %cond, ptr %x) {
-; CHECK-LABEL: @test_ret_ptr_nonnull_noundef_gep_inbounds_nonzero(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    call void @llvm.assume(i1 [[COND:%.*]])
-; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds ptr, ptr [[X:%.*]], i64 12
+; CHECK-NEXT:    [[GEP:%.*]] = getelementptr inbounds ptr, ptr [[SPEC_SELECT]], i64 12
 ; CHECK-NEXT:    ret ptr [[GEP]]
 ;
 entry: