[llvm] [ValueTracking] isNonEqual Pointers with with a recursive GEP (PR #70459)
via llvm-commits
llvm-commits at lists.llvm.org
Tue Dec 12 06:26:17 PST 2023
================
@@ -424,3 +424,427 @@ T:
F:
br label %T
}
+
+;Illustrate if 2 pointers are non-equal when one of them is a recursive GEP.
+;Cases which folds to a canonical icmp(ptr1, ptr2)
+define i1 @recursiveGEP_withPtrSub1(ptr noundef %val1) {
+; CHECK-LABEL: @recursiveGEP_withPtrSub1(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[WHILE_COND_I:%.*]]
+; CHECK: while.cond.i:
+; CHECK-NEXT: [[A_PN_I:%.*]] = phi ptr [ [[TEST_0_I:%.*]], [[WHILE_COND_I]] ], [ [[VAL1:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[TEST_0_I]] = getelementptr inbounds i8, ptr [[A_PN_I]], i64 1
+; CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[TEST_0_I]], align 2
+; CHECK-NEXT: [[CMP3_NOT_I:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT: br i1 [[CMP3_NOT_I]], label [[WHILE_END_I:%.*]], label [[WHILE_COND_I]]
+; CHECK: while.end.i:
+; CHECK-NEXT: ret i1 false
+;
+entry:
+ br label %while.cond.i
+
+while.cond.i:
+ %a.pn.i = phi ptr [ %test.0.i, %while.cond.i ], [ %val1, %entry ]
+ %test.0.i = getelementptr inbounds i8, ptr %a.pn.i, i64 1
+ %0 = load i8, ptr %test.0.i, align 2
+ %cmp3.not.i = icmp eq i8 %0, 0
+ br i1 %cmp3.not.i, label %while.end.i, label %while.cond.i
+
+while.end.i:
+ %sub.ptr.lhs.cast.i = ptrtoint ptr %test.0.i to i64
+ %sub.ptr.rhs.cast.i = ptrtoint ptr %val1 to i64
+ %sub.ptr.sub.i = sub i64 %sub.ptr.lhs.cast.i, %sub.ptr.rhs.cast.i
+ %bool = icmp eq i64 %sub.ptr.sub.i, 0
+ ret i1 %bool
+}
+
+define i1 @recursiveGEP_withPtrSub1_PhiOperandsCommuted(ptr noundef %val1) {
+; CHECK-LABEL: @recursiveGEP_withPtrSub1_PhiOperandsCommuted(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[WHILE_COND_I:%.*]]
+; CHECK: while.cond.i:
+; CHECK-NEXT: [[A_PN_I:%.*]] = phi ptr [ [[VAL1:%.*]], [[ENTRY:%.*]] ], [ [[TEST_0_I:%.*]], [[WHILE_COND_I]] ]
+; CHECK-NEXT: [[TEST_0_I]] = getelementptr inbounds i8, ptr [[A_PN_I]], i64 1
+; CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[TEST_0_I]], align 2
+; CHECK-NEXT: [[CMP3_NOT_I:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT: br i1 [[CMP3_NOT_I]], label [[WHILE_END_I:%.*]], label [[WHILE_COND_I]]
+; CHECK: while.end.i:
+; CHECK-NEXT: ret i1 false
+;
+entry:
+ br label %while.cond.i
+
+while.cond.i:
+ %a.pn.i = phi ptr [ %val1, %entry ], [ %test.0.i, %while.cond.i ]
+ %test.0.i = getelementptr inbounds i8, ptr %a.pn.i, i64 1
+ %0 = load i8, ptr %test.0.i, align 2
+ %cmp3.not.i = icmp eq i8 %0, 0
+ br i1 %cmp3.not.i, label %while.end.i, label %while.cond.i
+
+while.end.i:
+ %sub.ptr.lhs.cast.i = ptrtoint ptr %test.0.i to i64
+ %sub.ptr.rhs.cast.i = ptrtoint ptr %val1 to i64
+ %sub.ptr.sub.i = sub i64 %sub.ptr.lhs.cast.i, %sub.ptr.rhs.cast.i
+ %bool = icmp eq i64 %sub.ptr.sub.i, 0
+ ret i1 %bool
+}
+
+define i1 @recursiveGEP_withPtrSub1_SubOperandsCommuted(ptr noundef %val1) {
+; CHECK-LABEL: @recursiveGEP_withPtrSub1_SubOperandsCommuted(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[WHILE_COND_I:%.*]]
+; CHECK: while.cond.i:
+; CHECK-NEXT: [[A_PN_I:%.*]] = phi ptr [ [[TEST_0_I:%.*]], [[WHILE_COND_I]] ], [ [[VAL1:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[TEST_0_I]] = getelementptr inbounds i8, ptr [[A_PN_I]], i64 1
+; CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[TEST_0_I]], align 2
+; CHECK-NEXT: [[CMP3_NOT_I:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT: br i1 [[CMP3_NOT_I]], label [[WHILE_END_I:%.*]], label [[WHILE_COND_I]]
+; CHECK: while.end.i:
+; CHECK-NEXT: ret i1 false
+;
+entry:
+ br label %while.cond.i
+
+while.cond.i:
+ %a.pn.i = phi ptr [ %test.0.i, %while.cond.i ], [ %val1, %entry ]
+ %test.0.i = getelementptr inbounds i8, ptr %a.pn.i, i64 1
+ %0 = load i8, ptr %test.0.i, align 2
+ %cmp3.not.i = icmp eq i8 %0, 0
+ br i1 %cmp3.not.i, label %while.end.i, label %while.cond.i
+
+while.end.i:
+ %sub.ptr.lhs.cast.i = ptrtoint ptr %test.0.i to i64
+ %sub.ptr.rhs.cast.i = ptrtoint ptr %val1 to i64
+ %sub.ptr.sub.i = sub i64 %sub.ptr.rhs.cast.i, %sub.ptr.lhs.cast.i
+ %bool = icmp eq i64 %sub.ptr.sub.i, 0
+ ret i1 %bool
+}
+
+define i1 @recursiveGEP_withPtrSub2(ptr noundef %val1) {
+; CHECK-LABEL: @recursiveGEP_withPtrSub2(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[WHILE_COND_I:%.*]]
+; CHECK: while.cond.i:
+; CHECK-NEXT: [[A_PN_I:%.*]] = phi ptr [ [[TEST_0_I:%.*]], [[WHILE_COND_I]] ], [ [[VAL1:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[TEST_0_I]] = getelementptr inbounds i8, ptr [[A_PN_I]], i64 -1
+; CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[TEST_0_I]], align 2
+; CHECK-NEXT: [[CMP3_NOT_I:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT: br i1 [[CMP3_NOT_I]], label [[WHILE_END_I:%.*]], label [[WHILE_COND_I]]
+; CHECK: while.end.i:
+; CHECK-NEXT: ret i1 false
+;
+entry:
+ br label %while.cond.i
+
+while.cond.i:
+ %a.pn.i = phi ptr [ %test.0.i, %while.cond.i ], [ %val1, %entry ]
+ %test.0.i = getelementptr inbounds i8, ptr %a.pn.i, i64 -1
+ %0 = load i8, ptr %test.0.i, align 2
+ %cmp3.not.i = icmp eq i8 %0, 0
+ br i1 %cmp3.not.i, label %while.end.i, label %while.cond.i
+
+while.end.i:
+ %sub.ptr.lhs.cast.i = ptrtoint ptr %test.0.i to i64
+ %sub.ptr.rhs.cast.i = ptrtoint ptr %val1 to i64
+ %sub.ptr.sub.i = sub i64 %sub.ptr.lhs.cast.i, %sub.ptr.rhs.cast.i
+ %bool = icmp eq i64 %sub.ptr.sub.i, 0
+ ret i1 %bool
+}
+
+define i1 @recursiveGEP_withPtrSub3(ptr noundef %val1) {
+; CHECK-LABEL: @recursiveGEP_withPtrSub3(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[TEST_VAL1:%.*]] = getelementptr inbounds i8, ptr [[VAL1:%.*]], i64 7
+; CHECK-NEXT: br label [[WHILE_COND_I:%.*]]
+; CHECK: while.cond.i:
+; CHECK-NEXT: [[A_PN_I:%.*]] = phi ptr [ [[TEST_0_I:%.*]], [[WHILE_COND_I]] ], [ [[TEST_VAL1]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[TEST_0_I]] = getelementptr inbounds i8, ptr [[A_PN_I]], i64 1
+; CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[TEST_0_I]], align 2
+; CHECK-NEXT: [[CMP3_NOT_I:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT: br i1 [[CMP3_NOT_I]], label [[WHILE_END_I:%.*]], label [[WHILE_COND_I]]
+; CHECK: while.end.i:
+; CHECK-NEXT: ret i1 false
+;
+entry:
+ %test.val1 = getelementptr inbounds i8, ptr %val1, i64 7
+ br label %while.cond.i
+
+while.cond.i:
+ %a.pn.i = phi ptr [ %test.0.i, %while.cond.i ], [ %test.val1, %entry ]
+ %test.0.i = getelementptr inbounds i8, ptr %a.pn.i, i64 1
+ %0 = load i8, ptr %test.0.i, align 2
+ %cmp3.not.i = icmp eq i8 %0, 0
+ br i1 %cmp3.not.i, label %while.end.i, label %while.cond.i
+
+while.end.i:
+ %sub.ptr.lhs.cast.i = ptrtoint ptr %test.0.i to i64
+ %1 = getelementptr inbounds i8, ptr %val1, i64 5
+ %sub.ptr.rhs.cast.i = ptrtoint ptr %1 to i64
+ %sub.ptr.sub.i = sub i64 %sub.ptr.lhs.cast.i, %sub.ptr.rhs.cast.i
+ %bool = icmp eq i64 %sub.ptr.sub.i, 0
+ ret i1 %bool
+}
+
+define i1 @recursiveGEP_withPtrSub1_notKnownNonEqual1(ptr noundef %val1, i64 %val2) {
+; CHECK-LABEL: @recursiveGEP_withPtrSub1_notKnownNonEqual1(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[WHILE_COND_I:%.*]]
+; CHECK: while.cond.i:
+; CHECK-NEXT: [[A_PN_I:%.*]] = phi ptr [ [[TEST_0_I:%.*]], [[WHILE_COND_I]] ], [ [[VAL1:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[TEST_0_I]] = getelementptr inbounds i8, ptr [[A_PN_I]], i64 1
+; CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[TEST_0_I]], align 2
+; CHECK-NEXT: [[CMP3_NOT_I:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT: br i1 [[CMP3_NOT_I]], label [[WHILE_END_I:%.*]], label [[WHILE_COND_I]]
+; CHECK: while.end.i:
+; CHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds i8, ptr [[VAL1]], i64 [[VAL2:%.*]]
+; CHECK-NEXT: [[BOOL:%.*]] = icmp eq ptr [[TEST_0_I]], [[TMP1]]
+; CHECK-NEXT: ret i1 [[BOOL]]
+;
+entry:
+ br label %while.cond.i
+
+while.cond.i:
+ %a.pn.i = phi ptr [ %test.0.i, %while.cond.i ], [ %val1, %entry ]
+ %test.0.i = getelementptr inbounds i8, ptr %a.pn.i, i64 1
+ %0 = load i8, ptr %test.0.i, align 2
+ %cmp3.not.i = icmp eq i8 %0, 0
+ br i1 %cmp3.not.i, label %while.end.i, label %while.cond.i
+
+while.end.i:
+ %sub.ptr.lhs.cast.i = ptrtoint ptr %test.0.i to i64
+ %1 = getelementptr inbounds i8, ptr %val1, i64 %val2
+ %sub.ptr.rhs.cast.i = ptrtoint ptr %1 to i64
+ %sub.ptr.sub.i = sub i64 %sub.ptr.lhs.cast.i, %sub.ptr.rhs.cast.i
+ %bool = icmp eq i64 %sub.ptr.sub.i, 0
+ ret i1 %bool
+}
+
+define i1 @recursiveGEP_withPtrSub1_notKnownNonEqual2(ptr noundef %val1) {
+; CHECK-LABEL: @recursiveGEP_withPtrSub1_notKnownNonEqual2(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[TEST_VAL1:%.*]] = getelementptr inbounds i8, ptr [[VAL1:%.*]], i64 -1
+; CHECK-NEXT: br label [[WHILE_COND_I:%.*]]
+; CHECK: while.cond.i:
+; CHECK-NEXT: [[A_PN_I:%.*]] = phi ptr [ [[TEST_0_I:%.*]], [[WHILE_COND_I]] ], [ [[TEST_VAL1]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[TEST_0_I]] = getelementptr inbounds i8, ptr [[A_PN_I]], i64 1
+; CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[TEST_0_I]], align 2
+; CHECK-NEXT: [[CMP3_NOT_I:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT: br i1 [[CMP3_NOT_I]], label [[WHILE_END_I:%.*]], label [[WHILE_COND_I]]
+; CHECK: while.end.i:
+; CHECK-NEXT: [[BOOL:%.*]] = icmp eq ptr [[TEST_0_I]], [[VAL1]]
+; CHECK-NEXT: ret i1 [[BOOL]]
+;
+entry:
+ %test.val1 = getelementptr inbounds i8, ptr %val1, i64 -1
+ br label %while.cond.i
+
+while.cond.i:
+ %a.pn.i = phi ptr [ %test.0.i, %while.cond.i ], [ %test.val1, %entry ]
+ %test.0.i = getelementptr inbounds i8, ptr %a.pn.i, i64 1
+ %0 = load i8, ptr %test.0.i, align 2
+ %cmp3.not.i = icmp eq i8 %0, 0
+ br i1 %cmp3.not.i, label %while.end.i, label %while.cond.i
+
+while.end.i:
+ %sub.ptr.lhs.cast.i = ptrtoint ptr %test.0.i to i64
+ %sub.ptr.rhs.cast.i = ptrtoint ptr %val1 to i64
+ %sub.ptr.sub.i = sub i64 %sub.ptr.lhs.cast.i, %sub.ptr.rhs.cast.i
+ %bool = icmp eq i64 %sub.ptr.sub.i, 0
+ ret i1 %bool
+}
+
+define i1 @recursiveGEP_withPtrSub1_notKnownNonEqual3(ptr noundef %val1) {
+; CHECK-LABEL: @recursiveGEP_withPtrSub1_notKnownNonEqual3(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[TEST_VAL1:%.*]] = getelementptr inbounds i8, ptr [[VAL1:%.*]], i64 5
+; CHECK-NEXT: br label [[WHILE_COND_I:%.*]]
+; CHECK: while.cond.i:
+; CHECK-NEXT: [[A_PN_I:%.*]] = phi ptr [ [[TEST_0_I:%.*]], [[WHILE_COND_I]] ], [ [[TEST_VAL1]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[TEST_0_I]] = getelementptr inbounds i8, ptr [[A_PN_I]], i64 -1
+; CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[TEST_0_I]], align 2
+; CHECK-NEXT: [[CMP3_NOT_I:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT: br i1 [[CMP3_NOT_I]], label [[WHILE_END_I:%.*]], label [[WHILE_COND_I]]
+; CHECK: while.end.i:
+; CHECK-NEXT: [[BOOL:%.*]] = icmp eq ptr [[TEST_0_I]], [[VAL1]]
+; CHECK-NEXT: ret i1 [[BOOL]]
+;
+entry:
+ %test.val1 = getelementptr inbounds i8, ptr %val1, i64 5
+ br label %while.cond.i
+
+while.cond.i:
+ %a.pn.i = phi ptr [ %test.0.i, %while.cond.i ], [ %test.val1, %entry ]
+ %test.0.i = getelementptr inbounds i8, ptr %a.pn.i, i64 -1
+ %0 = load i8, ptr %test.0.i, align 2
+ %cmp3.not.i = icmp eq i8 %0, 0
+ br i1 %cmp3.not.i, label %while.end.i, label %while.cond.i
+
+while.end.i:
+ %sub.ptr.lhs.cast.i = ptrtoint ptr %test.0.i to i64
+ %sub.ptr.rhs.cast.i = ptrtoint ptr %val1 to i64
+ %sub.ptr.sub.i = sub i64 %sub.ptr.lhs.cast.i, %sub.ptr.rhs.cast.i
+ %bool = icmp eq i64 %sub.ptr.sub.i, 0
+ ret i1 %bool
+}
+
+define i1 @recursiveGEP_withPtrSub_maybeZero(ptr noundef %val1) {
+; CHECK-LABEL: @recursiveGEP_withPtrSub_maybeZero(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[WHILE_COND_I:%.*]]
+; CHECK: while.cond.i:
+; CHECK-NEXT: [[A_PN_I:%.*]] = phi ptr [ [[TEST_0_I:%.*]], [[WHILE_COND_I]] ], [ [[VAL1:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[A_PN_I]], align 2
+; CHECK-NEXT: [[TEST_0_I]] = getelementptr inbounds i8, ptr [[A_PN_I]], i64 1
+; CHECK-NEXT: [[CMP3_NOT_I:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT: br i1 [[CMP3_NOT_I]], label [[WHILE_END_I:%.*]], label [[WHILE_COND_I]]
+; CHECK: while.end.i:
+; CHECK-NEXT: [[BOOL:%.*]] = icmp eq ptr [[A_PN_I]], [[VAL1]]
+; CHECK-NEXT: ret i1 [[BOOL]]
+;
+entry:
+ br label %while.cond.i
+
+while.cond.i:
+ %a.pn.i = phi ptr [ %test.0.i, %while.cond.i ], [ %val1, %entry ]
+ %0 = load i8, ptr %a.pn.i, align 2
+ %test.0.i = getelementptr inbounds i8, ptr %a.pn.i, i64 1
+ %cmp3.not.i = icmp eq i8 %0, 0
+ br i1 %cmp3.not.i, label %while.end.i, label %while.cond.i
+
+while.end.i:
+ %sub.ptr.lhs.cast.i = ptrtoint ptr %a.pn.i to i64
+ %sub.ptr.rhs.cast.i = ptrtoint ptr %val1 to i64
+ %sub.ptr.sub.i = sub i64 %sub.ptr.lhs.cast.i, %sub.ptr.rhs.cast.i
+ %bool = icmp eq i64 %sub.ptr.sub.i, 0
+ ret i1 %bool
+}
+
+define i1 @recursiveGEP_withPtrSub_noninbound1(ptr noundef %val1) {
+; CHECK-LABEL: @recursiveGEP_withPtrSub_noninbound1(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[WHILE_COND_I:%.*]]
+; CHECK: while.cond.i:
+; CHECK-NEXT: [[A_PN_I:%.*]] = phi ptr [ [[TEST_0_I:%.*]], [[WHILE_COND_I]] ], [ [[VAL1:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[TEST_0_I]] = getelementptr i8, ptr [[A_PN_I]], i64 4294967297
+; CHECK-NEXT: [[TMP0:%.*]] = load i8, ptr [[TEST_0_I]], align 2
+; CHECK-NEXT: [[CMP3_NOT_I:%.*]] = icmp eq i8 [[TMP0]], 0
+; CHECK-NEXT: br i1 [[CMP3_NOT_I]], label [[WHILE_END_I:%.*]], label [[WHILE_COND_I]]
+; CHECK: while.end.i:
+; CHECK-NEXT: [[TEST_1_I:%.*]] = getelementptr i8, ptr [[VAL1]], i64 1
+; CHECK-NEXT: [[BOOL:%.*]] = icmp eq ptr [[TEST_0_I]], [[TEST_1_I]]
+; CHECK-NEXT: ret i1 [[BOOL]]
+;
+entry:
+ br label %while.cond.i
+
+while.cond.i:
+ %a.pn.i = phi ptr [ %test.0.i, %while.cond.i ], [ %val1, %entry ]
+ %test.0.i = getelementptr i8, ptr %a.pn.i, i64 4294967297
+ %0 = load i8, ptr %test.0.i, align 2
+ %cmp3.not.i = icmp eq i8 %0, 0
+ br i1 %cmp3.not.i, label %while.end.i, label %while.cond.i
+
+while.end.i:
+ %sub.ptr.lhs.cast.i = ptrtoint ptr %test.0.i to i64
+ %test.1.i = getelementptr i8, ptr %val1, i64 1
+ %sub.ptr.rhs.cast.i = ptrtoint ptr %test.1.i to i64
+ %sub.ptr.sub.i = sub i64 %sub.ptr.lhs.cast.i, %sub.ptr.rhs.cast.i
+ %bool = icmp eq i64 %sub.ptr.sub.i, 0
+ ret i1 %bool
+}
+
+define i1 @recursiveGEP_withPtrSub_noninbound2(ptr noundef %val1) {
----------------
bipmis wrote:
Thanks. I have added more test to showcase that this is being handled. Only exception to this is when exactly the same pointer is used for Start and Limit. Alternatively this can be handled by early check on Start/Limit being a non-inbound GEP.
https://github.com/llvm/llvm-project/pull/70459
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