[ValueTracking] Compute known bits from recursive select/phi #113707

dtcxzyw · 2024-10-25T16:26:38Z

This patch is inspired by #113686. I found that it removes a lot of unnecessary "and X, 1" in some applications that represent boolean values with int.

llvmbot · 2024-10-25T16:27:14Z

@llvm/pr-subscribers-backend-x86

@llvm/pr-subscribers-llvm-analysis

Author: Yingwei Zheng (dtcxzyw)

Changes

This patch is inspired by #113686. I found that it removes a lot of unnecessary "and X, 1" in some applications that represent boolean values with int.

Full diff: https://github.com/llvm/llvm-project/pull/113707.diff

2 Files Affected:

(modified) llvm/lib/Analysis/ValueTracking.cpp (+7)
(modified) llvm/test/Transforms/InstCombine/known-phi-recurse.ll (+115)

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index e9ed8b3c862b55..e443488a56b3cb 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -1566,6 +1566,13 @@ static void computeKnownBitsFromOperator(const Operator *I,
         // Skip direct self references.
         if (IncValue == P) continue;
 
+        // If the Use is a select of this phi, use the knownbit of the other
+        // operand to break the recursion.
+        Value *V;
+        if (match(IncValue, m_Select(m_Value(), m_Specific(P), m_Value(V))) ||
+            match(IncValue, m_Select(m_Value(), m_Value(V), m_Specific(P))))
+          IncValue = V;
+
         // Change the context instruction to the "edge" that flows into the
         // phi. This is important because that is where the value is actually
         // "evaluated" even though it is used later somewhere else. (see also
diff --git a/llvm/test/Transforms/InstCombine/known-phi-recurse.ll b/llvm/test/Transforms/InstCombine/known-phi-recurse.ll
index c2007d16ae93be..fd3728324b8ea8 100644
--- a/llvm/test/Transforms/InstCombine/known-phi-recurse.ll
+++ b/llvm/test/Transforms/InstCombine/known-phi-recurse.ll
@@ -142,3 +142,118 @@ end:
   ret i32 %res
 }
 
+define i32 @knownbits_phi_select_test1(ptr %p1, ptr %p2, i8 %x) {
+; CHECK-LABEL: @knownbits_phi_select_test1(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[INDVAR1:%.*]] = phi i8 [ [[LOAD2:%.*]], [[BB2:%.*]] ], [ [[X:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[INDVAR3:%.*]] = phi ptr [ [[INDVAR3_NEXT:%.*]], [[BB2]] ], [ [[P1:%.*]], [[ENTRY]] ]
+; CHECK-NEXT:    [[INDVAR4:%.*]] = phi i32 [ [[INDVAR4_NEXT:%.*]], [[BB2]] ], [ 0, [[ENTRY]] ]
+; CHECK-NEXT:    [[INDVAR5:%.*]] = phi i32 [ [[INDVAR5_NEXT:%.*]], [[BB2]] ], [ 0, [[ENTRY]] ]
+; CHECK-NEXT:    switch i8 [[INDVAR1]], label [[DEFAULT:%.*]] [
+; CHECK-NEXT:      i8 0, label [[EXIT:%.*]]
+; CHECK-NEXT:      i8 59, label [[BB1:%.*]]
+; CHECK-NEXT:      i8 35, label [[BB1]]
+; CHECK-NEXT:    ]
+; CHECK:       default:
+; CHECK-NEXT:    [[EXT:%.*]] = sext i8 [[INDVAR1]] to i64
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr inbounds i16, ptr [[P2:%.*]], i64 [[EXT]]
+; CHECK-NEXT:    [[LOAD1:%.*]] = load i16, ptr [[GEP1]], align 2
+; CHECK-NEXT:    [[MASK:%.*]] = and i16 [[LOAD1]], 8192
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i16 [[MASK]], 0
+; CHECK-NEXT:    br i1 [[CMP1]], label [[BB2]], label [[BB1]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ne i32 [[INDVAR4]], 0
+; CHECK-NEXT:    [[CMP3:%.*]] = icmp ne i32 [[INDVAR5]], 0
+; CHECK-NEXT:    [[OR_COND:%.*]] = select i1 [[CMP2]], i1 true, i1 [[CMP3]]
+; CHECK-NEXT:    br i1 [[OR_COND]], label [[BB2]], label [[EXIT]]
+; CHECK:       bb2:
+; CHECK-NEXT:    [[CMP4:%.*]] = icmp eq i8 [[INDVAR1]], 39
+; CHECK-NEXT:    [[EXT2:%.*]] = zext i1 [[CMP4]] to i32
+; CHECK-NEXT:    [[INDVAR4_NEXT]] = xor i32 [[INDVAR4]], [[EXT2]]
+; CHECK-NEXT:    [[CMP6:%.*]] = icmp eq i8 [[INDVAR1]], 34
+; CHECK-NEXT:    [[EXT3:%.*]] = zext i1 [[CMP6]] to i32
+; CHECK-NEXT:    [[INDVAR5_NEXT]] = xor i32 [[INDVAR5]], [[EXT3]]
+; CHECK-NEXT:    [[INDVAR3_NEXT]] = getelementptr inbounds i8, ptr [[INDVAR3]], i64 1
+; CHECK-NEXT:    [[LOAD2]] = load i8, ptr [[INDVAR3_NEXT]], align 1
+; CHECK-NEXT:    br label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i32 [[INDVAR5]]
+;
+entry:
+  br label %loop
+
+loop:
+  %indvar1 = phi i8 [ %load2, %bb2 ], [ %x, %entry ]
+  %indvar2 = phi i64 [ %indvar2.next, %bb2 ], [ 0, %entry ]
+  %indvar3 = phi ptr [ %indvar3.next, %bb2 ], [ %p1, %entry ]
+  %indvar4 = phi i32 [ %indvar4.next, %bb2 ], [ 0, %entry ]
+  %indvar5 = phi i32 [ %indvar5.next, %bb2 ], [ 0, %entry ]
+  switch i8 %indvar1, label %default [
+  i8 0, label %exit
+  i8 59, label %bb1
+  i8 35, label %bb1
+  ]
+
+default:
+  %ext = sext i8 %indvar1 to i64
+  %gep1 = getelementptr inbounds i16, ptr %p2, i64 %ext
+  %load1 = load i16, ptr %gep1, align 2
+  %mask = and i16 %load1, 8192
+  %cmp1 = icmp eq i16 %mask, 0
+  br i1 %cmp1, label %bb2, label %bb1
+
+bb1:
+  %cmp2 = icmp ne i32 %indvar4, 0
+  %cmp3 = icmp ne i32 %indvar5, 0
+  %or.cond = select i1 %cmp2, i1 true, i1 %cmp3
+  br i1 %or.cond, label %bb2, label %exit
+
+bb2:
+  %cmp4 = icmp eq i8 %indvar1, 39
+  %cmp5 = icmp eq i32 %indvar4, 0
+  %ext2 = zext i1 %cmp5 to i32
+  %indvar4.next = select i1 %cmp4, i32 %ext2, i32 %indvar4
+  %cmp6 = icmp eq i8 %indvar1, 34
+  %cmp7 = icmp eq i32 %indvar5, 0
+  %ext3 = zext i1 %cmp7 to i32
+  %indvar5.next = select i1 %cmp6, i32 %ext3, i32 %indvar5
+  %indvar3.next = getelementptr inbounds i8, ptr %indvar3, i64 1
+  %indvar2.next = add i64 %indvar2, 1
+  %load2 = load i8, ptr %indvar3.next, align 1
+  br label %loop
+
+exit:
+  ret i32 %indvar5
+}
+
+define i8 @knownbits_phi_select_test2() {
+; CHECK-LABEL: @knownbits_phi_select_test2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[INDVAR:%.*]] = phi i8 [ 0, [[ENTRY:%.*]] ], [ [[CONTAIN:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[COND0:%.*]] = call i1 @cond()
+; CHECK-NEXT:    [[CONTAIN]] = select i1 [[COND0]], i8 1, i8 [[INDVAR]]
+; CHECK-NEXT:    [[COND1:%.*]] = call i1 @cond()
+; CHECK-NEXT:    br i1 [[COND1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i8 [[CONTAIN]]
+;
+entry:
+  br label %loop
+
+loop:
+  %indvar = phi i8 [ 0, %entry ], [ %contain, %loop ]
+  %cond0 = call i1 @cond()
+  %contain = select i1 %cond0, i8 1, i8 %indvar
+  %cond1 = call i1 @cond()
+  br i1 %cond1, label %exit, label %loop
+
+exit:
+  %bool = and i8 %contain, 1
+  ret i8 %bool
+}
+
+declare i1 @cond()

llvmbot · 2024-10-25T16:27:15Z

@llvm/pr-subscribers-llvm-transforms

Author: Yingwei Zheng (dtcxzyw)

Changes

This patch is inspired by #113686. I found that it removes a lot of unnecessary "and X, 1" in some applications that represent boolean values with int.

Full diff: https://github.com/llvm/llvm-project/pull/113707.diff

2 Files Affected:

(modified) llvm/lib/Analysis/ValueTracking.cpp (+7)
(modified) llvm/test/Transforms/InstCombine/known-phi-recurse.ll (+115)

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index e9ed8b3c862b55..e443488a56b3cb 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -1566,6 +1566,13 @@ static void computeKnownBitsFromOperator(const Operator *I,
         // Skip direct self references.
         if (IncValue == P) continue;
 
+        // If the Use is a select of this phi, use the knownbit of the other
+        // operand to break the recursion.
+        Value *V;
+        if (match(IncValue, m_Select(m_Value(), m_Specific(P), m_Value(V))) ||
+            match(IncValue, m_Select(m_Value(), m_Value(V), m_Specific(P))))
+          IncValue = V;
+
         // Change the context instruction to the "edge" that flows into the
         // phi. This is important because that is where the value is actually
         // "evaluated" even though it is used later somewhere else. (see also
diff --git a/llvm/test/Transforms/InstCombine/known-phi-recurse.ll b/llvm/test/Transforms/InstCombine/known-phi-recurse.ll
index c2007d16ae93be..fd3728324b8ea8 100644
--- a/llvm/test/Transforms/InstCombine/known-phi-recurse.ll
+++ b/llvm/test/Transforms/InstCombine/known-phi-recurse.ll
@@ -142,3 +142,118 @@ end:
   ret i32 %res
 }
 
+define i32 @knownbits_phi_select_test1(ptr %p1, ptr %p2, i8 %x) {
+; CHECK-LABEL: @knownbits_phi_select_test1(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[INDVAR1:%.*]] = phi i8 [ [[LOAD2:%.*]], [[BB2:%.*]] ], [ [[X:%.*]], [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[INDVAR3:%.*]] = phi ptr [ [[INDVAR3_NEXT:%.*]], [[BB2]] ], [ [[P1:%.*]], [[ENTRY]] ]
+; CHECK-NEXT:    [[INDVAR4:%.*]] = phi i32 [ [[INDVAR4_NEXT:%.*]], [[BB2]] ], [ 0, [[ENTRY]] ]
+; CHECK-NEXT:    [[INDVAR5:%.*]] = phi i32 [ [[INDVAR5_NEXT:%.*]], [[BB2]] ], [ 0, [[ENTRY]] ]
+; CHECK-NEXT:    switch i8 [[INDVAR1]], label [[DEFAULT:%.*]] [
+; CHECK-NEXT:      i8 0, label [[EXIT:%.*]]
+; CHECK-NEXT:      i8 59, label [[BB1:%.*]]
+; CHECK-NEXT:      i8 35, label [[BB1]]
+; CHECK-NEXT:    ]
+; CHECK:       default:
+; CHECK-NEXT:    [[EXT:%.*]] = sext i8 [[INDVAR1]] to i64
+; CHECK-NEXT:    [[GEP1:%.*]] = getelementptr inbounds i16, ptr [[P2:%.*]], i64 [[EXT]]
+; CHECK-NEXT:    [[LOAD1:%.*]] = load i16, ptr [[GEP1]], align 2
+; CHECK-NEXT:    [[MASK:%.*]] = and i16 [[LOAD1]], 8192
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i16 [[MASK]], 0
+; CHECK-NEXT:    br i1 [[CMP1]], label [[BB2]], label [[BB1]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[CMP2:%.*]] = icmp ne i32 [[INDVAR4]], 0
+; CHECK-NEXT:    [[CMP3:%.*]] = icmp ne i32 [[INDVAR5]], 0
+; CHECK-NEXT:    [[OR_COND:%.*]] = select i1 [[CMP2]], i1 true, i1 [[CMP3]]
+; CHECK-NEXT:    br i1 [[OR_COND]], label [[BB2]], label [[EXIT]]
+; CHECK:       bb2:
+; CHECK-NEXT:    [[CMP4:%.*]] = icmp eq i8 [[INDVAR1]], 39
+; CHECK-NEXT:    [[EXT2:%.*]] = zext i1 [[CMP4]] to i32
+; CHECK-NEXT:    [[INDVAR4_NEXT]] = xor i32 [[INDVAR4]], [[EXT2]]
+; CHECK-NEXT:    [[CMP6:%.*]] = icmp eq i8 [[INDVAR1]], 34
+; CHECK-NEXT:    [[EXT3:%.*]] = zext i1 [[CMP6]] to i32
+; CHECK-NEXT:    [[INDVAR5_NEXT]] = xor i32 [[INDVAR5]], [[EXT3]]
+; CHECK-NEXT:    [[INDVAR3_NEXT]] = getelementptr inbounds i8, ptr [[INDVAR3]], i64 1
+; CHECK-NEXT:    [[LOAD2]] = load i8, ptr [[INDVAR3_NEXT]], align 1
+; CHECK-NEXT:    br label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i32 [[INDVAR5]]
+;
+entry:
+  br label %loop
+
+loop:
+  %indvar1 = phi i8 [ %load2, %bb2 ], [ %x, %entry ]
+  %indvar2 = phi i64 [ %indvar2.next, %bb2 ], [ 0, %entry ]
+  %indvar3 = phi ptr [ %indvar3.next, %bb2 ], [ %p1, %entry ]
+  %indvar4 = phi i32 [ %indvar4.next, %bb2 ], [ 0, %entry ]
+  %indvar5 = phi i32 [ %indvar5.next, %bb2 ], [ 0, %entry ]
+  switch i8 %indvar1, label %default [
+  i8 0, label %exit
+  i8 59, label %bb1
+  i8 35, label %bb1
+  ]
+
+default:
+  %ext = sext i8 %indvar1 to i64
+  %gep1 = getelementptr inbounds i16, ptr %p2, i64 %ext
+  %load1 = load i16, ptr %gep1, align 2
+  %mask = and i16 %load1, 8192
+  %cmp1 = icmp eq i16 %mask, 0
+  br i1 %cmp1, label %bb2, label %bb1
+
+bb1:
+  %cmp2 = icmp ne i32 %indvar4, 0
+  %cmp3 = icmp ne i32 %indvar5, 0
+  %or.cond = select i1 %cmp2, i1 true, i1 %cmp3
+  br i1 %or.cond, label %bb2, label %exit
+
+bb2:
+  %cmp4 = icmp eq i8 %indvar1, 39
+  %cmp5 = icmp eq i32 %indvar4, 0
+  %ext2 = zext i1 %cmp5 to i32
+  %indvar4.next = select i1 %cmp4, i32 %ext2, i32 %indvar4
+  %cmp6 = icmp eq i8 %indvar1, 34
+  %cmp7 = icmp eq i32 %indvar5, 0
+  %ext3 = zext i1 %cmp7 to i32
+  %indvar5.next = select i1 %cmp6, i32 %ext3, i32 %indvar5
+  %indvar3.next = getelementptr inbounds i8, ptr %indvar3, i64 1
+  %indvar2.next = add i64 %indvar2, 1
+  %load2 = load i8, ptr %indvar3.next, align 1
+  br label %loop
+
+exit:
+  ret i32 %indvar5
+}
+
+define i8 @knownbits_phi_select_test2() {
+; CHECK-LABEL: @knownbits_phi_select_test2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[INDVAR:%.*]] = phi i8 [ 0, [[ENTRY:%.*]] ], [ [[CONTAIN:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[COND0:%.*]] = call i1 @cond()
+; CHECK-NEXT:    [[CONTAIN]] = select i1 [[COND0]], i8 1, i8 [[INDVAR]]
+; CHECK-NEXT:    [[COND1:%.*]] = call i1 @cond()
+; CHECK-NEXT:    br i1 [[COND1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i8 [[CONTAIN]]
+;
+entry:
+  br label %loop
+
+loop:
+  %indvar = phi i8 [ 0, %entry ], [ %contain, %loop ]
+  %cond0 = call i1 @cond()
+  %contain = select i1 %cond0, i8 1, i8 %indvar
+  %cond1 = call i1 @cond()
+  br i1 %cond1, label %exit, label %loop
+
+exit:
+  %bool = and i8 %contain, 1
+  ret i8 %bool
+}
+
+declare i1 @cond()

goldsteinn · 2024-10-25T17:24:59Z

This looks fine although I have two notes.

since we are sure to be breaking the recursion here we can probably do a full depth computeKnownBits below.
it would be nice if we could also use the selects compare context.

dtcxzyw · 2024-10-26T14:58:44Z

it would be nice if we could also use the selects compare context.

Looks like it breaks the stage2 build.

dtcxzyw · 2024-10-26T16:27:48Z

it would be nice if we could also use the selects compare context.

It doesn't improve anything (with +0.01% compile-time overhead). Should I drop it?

goldsteinn · 2024-10-26T19:13:25Z

it would be nice if we could also use the selects compare context.

It doesn't improve anything (with +0.01% compile-time overhead). Should I drop it?

If it doesn't improve anything ~~yeah~~ up to you, although IMO leave a comment explaining as much.

Edit: Typically I prefer completeness, although I can't really argue on behalf of the change if there are
no changes from it except a minor compile time disadvantage.

goldsteinn

LGTM like this or if you want to revert to prior version.

goldsteinn · 2024-10-30T15:03:57Z

Are you going to update to handle #114008.
If not I can post a patch after you merge this.

dtcxzyw · 2024-10-30T15:11:46Z

Are you going to update to handle #114008. If not I can post a patch after you merge this.

No, feel free to do this :)

Finish porting llvm#114008 to `KnownBits` (Follow up to llvm#113707).

…3707) This patch is inspired by llvm#113686. I found that it removes a lot of unnecessary "and X, 1" in some applications that represent boolean values with int.

Finish porting llvm#114008 to `KnownBits` (Follow up to llvm#113707).

nikic · 2024-11-03T11:12:24Z

llvm/lib/Analysis/ValueTracking.cpp

+          if (SI->getTrueValue() == P || SI->getFalseValue() == P) {
+            IncValue = SI->getTrueValue() == P ? SI->getFalseValue()
+                                               : SI->getTrueValue();
+            IncDepth = Depth + 1;


Forwarding the question from #114689 (review) because the issue was introduced here: Why do we use the full depth for the select case?

As far as I can tell, a) there may be multiple incoming values in this form, resulting in a fan-out problem and b) we are not actually guaranteed that this breaks recursion (because the other select operand may also be based on the phi indirectly) so the fan-out may be recursive as well.

Answered in #114689 (comment), lets keep the conversion in one place.

…3707) This patch is inspired by llvm#113686. I found that it removes a lot of unnecessary "and X, 1" in some applications that represent boolean values with int.

As discussed on llvm#114689 (review) and following, there is no principled reason why the phi of select case should have a different recursion limit than the general case. There may still be fan-out, and there may still be indirect recursion. Revert that part of llvm#113707.

As discussed on #114689 (review) and following, there is no principled reason why the phi of select case should have a different recursion limit than the general case. There may still be fan-out, and there may still be indirect recursion. Revert that part of #113707.

As discussed on llvm#114689 (review) and following, there is no principled reason why the phi of select case should have a different recursion limit than the general case. There may still be fan-out, and there may still be indirect recursion. Revert that part of llvm#113707.

Finish porting llvm#114008 to `KnownBits` (Follow up to llvm#113707).

) Finish porting #114008 to `KnownBits` (Follow up to #113707).

dtcxzyw added 2 commits October 26, 2024 00:16

[InstCombine] Add pre-commit tests. NFC.

5f0ad32

[ValueTracking] Compute known bits from recursive select/phi

015584b

dtcxzyw requested review from davemgreen and goldsteinn October 25, 2024 16:26

dtcxzyw requested a review from nikic as a code owner October 25, 2024 16:26

llvmbot added llvm:analysis llvm:transforms labels Oct 25, 2024

dtcxzyw mentioned this pull request Oct 25, 2024

Task submission dtcxzyw/llvm-opt-benchmark#1312

Open

This was referenced Oct 25, 2024

Fuzz PR113707 dtcxzyw/llvm-fuzz-service#27

Closed

pre-commit: PR113707 dtcxzyw/llvm-opt-benchmark#1535

Closed

[ValueTracking] Increase recursion depth. NFC.

b66b3ca

dtcxzyw mentioned this pull request Oct 26, 2024

pre-commit: PR113707 dtcxzyw/llvm-opt-benchmark#1540

Closed

dtcxzyw added 2 commits October 26, 2024 20:06

[ValueTracking] Adjust comments. NFC.

d990feb

[ValueTracking] Adjust known bits from select's condition

5751edb

llvmbot added the backend:X86 label Oct 26, 2024

dtcxzyw mentioned this pull request Oct 26, 2024

pre-commit: PR113707 dtcxzyw/llvm-opt-benchmark#1541

Closed

dtcxzyw added 2 commits October 26, 2024 23:28

[ValueTracking] Fix depth

a5567a2

[ValueTracking] Fix miscompilation

51f9734

dtcxzyw mentioned this pull request Oct 26, 2024

pre-commit: PR113707 dtcxzyw/llvm-opt-benchmark#1542

Closed

goldsteinn approved these changes Oct 26, 2024

View reviewed changes

[ValueTracking] Don't infer known bits from select arms

5513100

dtcxzyw merged commit f1e1055 into llvm:main Nov 2, 2024
8 checks passed

dtcxzyw deleted the perf/knownbits-phi-select branch November 2, 2024 07:45

goldsteinn added a commit to goldsteinn/llvm-project that referenced this pull request Nov 3, 2024

[ValueTracking] Handle recursive PHI's in computeKnownBits

fb0ed3b

Finish porting llvm#114008 to `KnownBits` (Follow up to llvm#113707).

goldsteinn mentioned this pull request Nov 3, 2024

[ValueTracking] Handle recursive select/PHI in ComputeKnownBits #114689

Merged

goldsteinn added a commit to goldsteinn/llvm-project that referenced this pull request Nov 3, 2024

[ValueTracking] Handle recursive PHI's in computeKnownBits

cc5208b

Finish porting llvm#114008 to `KnownBits` (Follow up to llvm#113707).

goldsteinn added a commit to goldsteinn/llvm-project that referenced this pull request Nov 3, 2024

[ValueTracking] Handle recursive PHI's in computeKnownBits

7294978

Finish porting llvm#114008 to `KnownBits` (Follow up to llvm#113707).

nikic reviewed Nov 3, 2024

View reviewed changes

nikic mentioned this pull request Nov 5, 2024

[ValueTracking] Don't special case depth for phi of select #114996

Merged

goldsteinn added a commit to goldsteinn/llvm-project that referenced this pull request Jan 11, 2025

[ValueTracking] Handle recursive PHI's in computeKnownBits

256d0ee

Finish porting llvm#114008 to `KnownBits` (Follow up to llvm#113707).

goldsteinn added a commit that referenced this pull request Jan 22, 2025

[ValueTracking] Handle recursive select/PHI in ComputeKnownBits (#114689

a56ba1f

) Finish porting #114008 to `KnownBits` (Follow up to #113707).

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

[ValueTracking] Compute known bits from recursive select/phi #113707

[ValueTracking] Compute known bits from recursive select/phi #113707

Uh oh!

dtcxzyw commented Oct 25, 2024

Uh oh!

llvmbot commented Oct 25, 2024 •

edited

Loading

Uh oh!

llvmbot commented Oct 25, 2024

Uh oh!

goldsteinn commented Oct 25, 2024

Uh oh!

dtcxzyw commented Oct 26, 2024

Uh oh!

dtcxzyw commented Oct 26, 2024

Uh oh!

goldsteinn commented Oct 26, 2024 •

edited

Loading

Uh oh!

goldsteinn left a comment

Uh oh!

goldsteinn commented Oct 30, 2024

Uh oh!

dtcxzyw commented Oct 30, 2024

Uh oh!

Uh oh!

nikic Nov 3, 2024

Uh oh!

goldsteinn Nov 3, 2024

Uh oh!

Uh oh!

[ValueTracking] Compute known bits from recursive select/phi #113707

[ValueTracking] Compute known bits from recursive select/phi #113707

Uh oh!

Conversation

dtcxzyw commented Oct 25, 2024

Uh oh!

llvmbot commented Oct 25, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

llvmbot commented Oct 25, 2024

Uh oh!

goldsteinn commented Oct 25, 2024

Uh oh!

dtcxzyw commented Oct 26, 2024

Uh oh!

dtcxzyw commented Oct 26, 2024

Uh oh!

goldsteinn commented Oct 26, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

goldsteinn left a comment

Choose a reason for hiding this comment

Uh oh!

goldsteinn commented Oct 30, 2024

Uh oh!

dtcxzyw commented Oct 30, 2024

Uh oh!

Uh oh!

nikic Nov 3, 2024

Choose a reason for hiding this comment

Uh oh!

goldsteinn Nov 3, 2024

Choose a reason for hiding this comment

Uh oh!

Uh oh!

llvmbot commented Oct 25, 2024 •

edited

Loading

goldsteinn commented Oct 26, 2024 •

edited

Loading