[llvm] [InstCombie] Add folds for (icmp eq/ne (and (add/sub/xor A, P2), P2), 0/P2) (PR #67836)
via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 29 12:03:33 PDT 2023
https://github.com/goldsteinn updated https://github.com/llvm/llvm-project/pull/67836
>From d016e35f057455f42a800247ced056a0d0fc06e2 Mon Sep 17 00:00:00 2001
From: Noah Goldstein <goldstein.w.n at gmail.com>
Date: Fri, 29 Sep 2023 11:45:09 -0500
Subject: [PATCH 1/2] [InstCombine] Add tests for folding (icmp eq/ne (and
(add/sub/xor A, P2), P2), 0/P2); NFC
---
.../InstCombine/icmp-and-add-sub-xor-p2.ll | 124 ++++++++++++++++++
1 file changed, 124 insertions(+)
create mode 100644 llvm/test/Transforms/InstCombine/icmp-and-add-sub-xor-p2.ll
diff --git a/llvm/test/Transforms/InstCombine/icmp-and-add-sub-xor-p2.ll b/llvm/test/Transforms/InstCombine/icmp-and-add-sub-xor-p2.ll
new file mode 100644
index 000000000000000..e6724b295654436
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/icmp-and-add-sub-xor-p2.ll
@@ -0,0 +1,124 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -passes=instcombine -S -o - %s | FileCheck %s
+
+declare void @use.i8(i8)
+define i1 @src_add_eq_p2(i8 %x, i8 %yy) {
+; CHECK-LABEL: @src_add_eq_p2(
+; CHECK-NEXT: [[NY:%.*]] = sub i8 0, [[YY:%.*]]
+; CHECK-NEXT: [[Y:%.*]] = and i8 [[NY]], [[YY]]
+; CHECK-NEXT: [[X1:%.*]] = add i8 [[Y]], [[X:%.*]]
+; CHECK-NEXT: [[V:%.*]] = and i8 [[X1]], [[Y]]
+; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[V]], [[Y]]
+; CHECK-NEXT: ret i1 [[R]]
+;
+ %ny = sub i8 0, %yy
+ %y = and i8 %ny, %yy
+ %x1 = add i8 %x, %y
+ %v = and i8 %x1, %y
+ %r = icmp eq i8 %v, %y
+ ret i1 %r
+}
+
+define i1 @src_add_eq_p2_fail_multiuse(i8 %x, i8 %yy) {
+; CHECK-LABEL: @src_add_eq_p2_fail_multiuse(
+; CHECK-NEXT: [[NY:%.*]] = sub i8 0, [[YY:%.*]]
+; CHECK-NEXT: [[Y:%.*]] = and i8 [[NY]], [[YY]]
+; CHECK-NEXT: [[X1:%.*]] = add i8 [[Y]], [[X:%.*]]
+; CHECK-NEXT: [[V:%.*]] = and i8 [[X1]], [[Y]]
+; CHECK-NEXT: call void @use.i8(i8 [[V]])
+; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[V]], [[Y]]
+; CHECK-NEXT: ret i1 [[R]]
+;
+ %ny = sub i8 0, %yy
+ %y = and i8 %ny, %yy
+ %x1 = add i8 %x, %y
+ %v = and i8 %x1, %y
+ call void @use.i8(i8 %v)
+ %r = icmp eq i8 %v, %y
+ ret i1 %r
+}
+
+define i1 @src_xor_ne_zero(i8 %x, i8 %yy) {
+; CHECK-LABEL: @src_xor_ne_zero(
+; CHECK-NEXT: [[NY:%.*]] = sub i8 0, [[YY:%.*]]
+; CHECK-NEXT: [[Y:%.*]] = and i8 [[NY]], [[YY]]
+; CHECK-NEXT: [[X1:%.*]] = xor i8 [[Y]], [[X:%.*]]
+; CHECK-NEXT: call void @use.i8(i8 [[X1]])
+; CHECK-NEXT: [[V:%.*]] = and i8 [[X1]], [[Y]]
+; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[V]], 0
+; CHECK-NEXT: ret i1 [[R]]
+;
+ %ny = sub i8 0, %yy
+ %y = and i8 %ny, %yy
+ %x1 = xor i8 %x, %y
+ call void @use.i8(i8 %x1)
+ %v = and i8 %x1, %y
+ %r = icmp ne i8 %v, 0
+ ret i1 %r
+}
+
+define i1 @src_xor_ne_zero_fail_different_p2(i8 %x, i8 %yy) {
+; CHECK-LABEL: @src_xor_ne_zero_fail_different_p2(
+; CHECK-NEXT: [[NY:%.*]] = sub i8 0, [[YY:%.*]]
+; CHECK-NEXT: [[Y:%.*]] = and i8 [[NY]], [[YY]]
+; CHECK-NEXT: [[Y2:%.*]] = shl i8 [[Y]], 1
+; CHECK-NEXT: [[X1:%.*]] = xor i8 [[Y]], [[X:%.*]]
+; CHECK-NEXT: [[V:%.*]] = and i8 [[X1]], [[Y2]]
+; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[V]], 0
+; CHECK-NEXT: ret i1 [[R]]
+;
+ %ny = sub i8 0, %yy
+ %y = and i8 %ny, %yy
+ %y2 = shl i8 %y, 1
+ %x1 = xor i8 %x, %y
+ %v = and i8 %x1, %y2
+ %r = icmp ne i8 %v, 0
+ ret i1 %r
+}
+
+define <2 x i1> @src_sub_ne_p2(<2 x i8> %x, <2 x i8> %yy) {
+; CHECK-LABEL: @src_sub_ne_p2(
+; CHECK-NEXT: [[NY:%.*]] = sub <2 x i8> zeroinitializer, [[YY:%.*]]
+; CHECK-NEXT: [[Y:%.*]] = and <2 x i8> [[NY]], [[YY]]
+; CHECK-NEXT: [[X1:%.*]] = sub <2 x i8> [[X:%.*]], [[Y]]
+; CHECK-NEXT: [[V:%.*]] = and <2 x i8> [[X1]], [[Y]]
+; CHECK-NEXT: [[R:%.*]] = icmp ne <2 x i8> [[V]], [[Y]]
+; CHECK-NEXT: ret <2 x i1> [[R]]
+;
+ %ny = sub <2 x i8> zeroinitializer, %yy
+ %y = and <2 x i8> %ny, %yy
+ %x1 = sub <2 x i8> %x, %y
+ %v = and <2 x i8> %x1, %y
+ %r = icmp ne <2 x i8> %v, %y
+ ret <2 x i1> %r
+}
+
+define <2 x i1> @src_sub_eq_zero(<2 x i8> %x, <2 x i8> %yy) {
+; CHECK-LABEL: @src_sub_eq_zero(
+; CHECK-NEXT: [[Y:%.*]] = shl <2 x i8> <i8 1, i8 2>, [[YY:%.*]]
+; CHECK-NEXT: [[X1:%.*]] = sub <2 x i8> [[X:%.*]], [[Y]]
+; CHECK-NEXT: [[V:%.*]] = and <2 x i8> [[X1]], [[Y]]
+; CHECK-NEXT: [[R:%.*]] = icmp eq <2 x i8> [[V]], zeroinitializer
+; CHECK-NEXT: ret <2 x i1> [[R]]
+;
+ %y = shl <2 x i8> <i8 1, i8 2>, %yy
+ %x1 = sub <2 x i8> %x, %y
+ %v = and <2 x i8> %x1, %y
+ %r = icmp eq <2 x i8> %v, zeroinitializer
+ ret <2 x i1> %r
+}
+
+define <2 x i1> @src_sub_eq_zero_fail_non_p2(<2 x i8> %x, <2 x i8> %yy) {
+; CHECK-LABEL: @src_sub_eq_zero_fail_non_p2(
+; CHECK-NEXT: [[Y:%.*]] = shl <2 x i8> <i8 1, i8 3>, [[YY:%.*]]
+; CHECK-NEXT: [[X1:%.*]] = sub <2 x i8> [[X:%.*]], [[Y]]
+; CHECK-NEXT: [[V:%.*]] = and <2 x i8> [[X1]], [[Y]]
+; CHECK-NEXT: [[R:%.*]] = icmp eq <2 x i8> [[V]], zeroinitializer
+; CHECK-NEXT: ret <2 x i1> [[R]]
+;
+ %y = shl <2 x i8> <i8 1, i8 3>, %yy
+ %x1 = sub <2 x i8> %x, %y
+ %v = and <2 x i8> %x1, %y
+ %r = icmp eq <2 x i8> %v, zeroinitializer
+ ret <2 x i1> %r
+}
>From 914ee8edf95035f20a5fa78f20acb90a95c7b9bb Mon Sep 17 00:00:00 2001
From: Noah Goldstein <goldstein.w.n at gmail.com>
Date: Fri, 29 Sep 2023 11:45:15 -0500
Subject: [PATCH 2/2] [InstCombine] Add folds for (icmp eq/ne (and (add/sub/xor
A, P2), P2), 0/P2)
- `(icmp eq/ne (and (add/sub/xor X, P2), P2), P2)`
-> `(icmp eq/ne (and X, P2), 0)`
- `(icmp eq/ne (and (add/sub/xor X, P2), P2), 0)`
-> `(icmp eq/ne (and X, P2), P2)`
Folds like this come up with reasonable regularity in odd/even loops.
Proofs: https://alive2.llvm.org/ce/z/45pq2x
---
.../InstCombine/InstCombineCompares.cpp | 40 +++++++++++++++++++
.../InstCombine/icmp-and-add-sub-xor-p2.ll | 23 +++++------
llvm/test/Transforms/InstCombine/pr25342.ll | 12 +++---
.../PGOProfile/cspgo_profile_summary.ll | 2 +-
4 files changed, 57 insertions(+), 20 deletions(-)
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 9f034aba874a8c4..d543703fc61471a 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -5453,6 +5453,46 @@ Instruction *InstCombinerImpl::foldICmpEquality(ICmpInst &I) {
m_CombineAnd(m_Value(B), m_Unless(m_ImmConstant())))))
return new ICmpInst(Pred, Builder.CreateXor(A, B), Cst);
+ {
+ auto MatchAndP2OfAddSubXor = [&](unsigned Opc) -> std::optional<bool> {
+ // (icmp eq/ne (and (add/sub/xor X, P2), P2), P2)
+ std::optional<bool> Matched = std::nullopt;
+ if (match(&I, m_c_ICmp(
+ PredUnused,
+ m_OneUse(m_c_And(m_Value(A), m_c_BinOp(Opc, m_Value(B),
+ m_Deferred(A)))),
+ m_Deferred(A))))
+ Matched = false;
+ // (icmp eq/ne (and (add/sub/xor X, P2), P2), 0)
+ else if (match(&I, m_ICmp(PredUnused,
+ m_OneUse(m_c_And(
+ m_Value(A),
+ m_c_BinOp(Opc, m_Value(B), m_Deferred(A)))),
+ m_Zero())))
+ Matched = true;
+
+ if (Matched &&
+ isKnownToBeAPowerOfTwo(A, /* OrZero */ true, /*Depth*/ 0, &I))
+ return Matched;
+ return std::nullopt;
+ };
+ std::optional<bool> IsZero = MatchAndP2OfAddSubXor(Instruction::Add);
+ if (!IsZero)
+ IsZero = MatchAndP2OfAddSubXor(Instruction::Sub);
+ if (!IsZero)
+ IsZero = MatchAndP2OfAddSubXor(Instruction::Xor);
+
+ if (IsZero) {
+ // (icmp eq/ne (and (add/sub/xor X, P2), P2), P2)
+ // -> (icmp eq/ne (and X, P2), 0)
+ // (icmp eq/ne (and (add/sub/xor X, P2), P2), 0)
+ // -> (icmp eq/ne (and X, P2), P2)
+ return new ICmpInst(Pred, Builder.CreateAnd(B, A),
+ *IsZero ? A
+ : ConstantInt::getNullValue(A->getType()));
+ }
+ }
+
return nullptr;
}
diff --git a/llvm/test/Transforms/InstCombine/icmp-and-add-sub-xor-p2.ll b/llvm/test/Transforms/InstCombine/icmp-and-add-sub-xor-p2.ll
index e6724b295654436..590113179bab418 100644
--- a/llvm/test/Transforms/InstCombine/icmp-and-add-sub-xor-p2.ll
+++ b/llvm/test/Transforms/InstCombine/icmp-and-add-sub-xor-p2.ll
@@ -5,10 +5,9 @@ declare void @use.i8(i8)
define i1 @src_add_eq_p2(i8 %x, i8 %yy) {
; CHECK-LABEL: @src_add_eq_p2(
; CHECK-NEXT: [[NY:%.*]] = sub i8 0, [[YY:%.*]]
-; CHECK-NEXT: [[Y:%.*]] = and i8 [[NY]], [[YY]]
-; CHECK-NEXT: [[X1:%.*]] = add i8 [[Y]], [[X:%.*]]
-; CHECK-NEXT: [[V:%.*]] = and i8 [[X1]], [[Y]]
-; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[V]], [[Y]]
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[NY]], [[X:%.*]]
+; CHECK-NEXT: [[TMP2:%.*]] = and i8 [[TMP1]], [[YY]]
+; CHECK-NEXT: [[R:%.*]] = icmp eq i8 [[TMP2]], 0
; CHECK-NEXT: ret i1 [[R]]
;
%ny = sub i8 0, %yy
@@ -44,8 +43,8 @@ define i1 @src_xor_ne_zero(i8 %x, i8 %yy) {
; CHECK-NEXT: [[Y:%.*]] = and i8 [[NY]], [[YY]]
; CHECK-NEXT: [[X1:%.*]] = xor i8 [[Y]], [[X:%.*]]
; CHECK-NEXT: call void @use.i8(i8 [[X1]])
-; CHECK-NEXT: [[V:%.*]] = and i8 [[X1]], [[Y]]
-; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[V]], 0
+; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[Y]], [[X]]
+; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[TMP1]], [[Y]]
; CHECK-NEXT: ret i1 [[R]]
;
%ny = sub i8 0, %yy
@@ -79,10 +78,9 @@ define i1 @src_xor_ne_zero_fail_different_p2(i8 %x, i8 %yy) {
define <2 x i1> @src_sub_ne_p2(<2 x i8> %x, <2 x i8> %yy) {
; CHECK-LABEL: @src_sub_ne_p2(
; CHECK-NEXT: [[NY:%.*]] = sub <2 x i8> zeroinitializer, [[YY:%.*]]
-; CHECK-NEXT: [[Y:%.*]] = and <2 x i8> [[NY]], [[YY]]
-; CHECK-NEXT: [[X1:%.*]] = sub <2 x i8> [[X:%.*]], [[Y]]
-; CHECK-NEXT: [[V:%.*]] = and <2 x i8> [[X1]], [[Y]]
-; CHECK-NEXT: [[R:%.*]] = icmp ne <2 x i8> [[V]], [[Y]]
+; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i8> [[NY]], [[X:%.*]]
+; CHECK-NEXT: [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[YY]]
+; CHECK-NEXT: [[R:%.*]] = icmp ne <2 x i8> [[TMP2]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[R]]
;
%ny = sub <2 x i8> zeroinitializer, %yy
@@ -96,9 +94,8 @@ define <2 x i1> @src_sub_ne_p2(<2 x i8> %x, <2 x i8> %yy) {
define <2 x i1> @src_sub_eq_zero(<2 x i8> %x, <2 x i8> %yy) {
; CHECK-LABEL: @src_sub_eq_zero(
; CHECK-NEXT: [[Y:%.*]] = shl <2 x i8> <i8 1, i8 2>, [[YY:%.*]]
-; CHECK-NEXT: [[X1:%.*]] = sub <2 x i8> [[X:%.*]], [[Y]]
-; CHECK-NEXT: [[V:%.*]] = and <2 x i8> [[X1]], [[Y]]
-; CHECK-NEXT: [[R:%.*]] = icmp eq <2 x i8> [[V]], zeroinitializer
+; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i8> [[Y]], [[X:%.*]]
+; CHECK-NEXT: [[R:%.*]] = icmp eq <2 x i8> [[TMP1]], [[Y]]
; CHECK-NEXT: ret <2 x i1> [[R]]
;
%y = shl <2 x i8> <i8 1, i8 2>, %yy
diff --git a/llvm/test/Transforms/InstCombine/pr25342.ll b/llvm/test/Transforms/InstCombine/pr25342.ll
index e1a6822e7908474..2f85f99c4ce003e 100644
--- a/llvm/test/Transforms/InstCombine/pr25342.ll
+++ b/llvm/test/Transforms/InstCombine/pr25342.ll
@@ -78,7 +78,7 @@ define void @multi_phi(i32 signext %n) {
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[FOR_COND:%.*]]
; CHECK: for.cond:
-; CHECK-NEXT: [[TMP0:%.*]] = phi float [ 0.000000e+00, [[ENTRY:%.*]] ], [ [[TMP6:%.*]], [[ODD_BB:%.*]] ]
+; CHECK-NEXT: [[TMP0:%.*]] = phi float [ 0.000000e+00, [[ENTRY:%.*]] ], [ [[TMP7:%.*]], [[ODD_BB:%.*]] ]
; CHECK-NEXT: [[I_0:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC:%.*]], [[ODD_BB]] ]
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[I_0]], [[N:%.*]]
; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY:%.*]], label [[FOR_END:%.*]]
@@ -92,14 +92,14 @@ define void @multi_phi(i32 signext %n) {
; CHECK-NEXT: [[SUB_I:%.*]] = fsub float [[MUL_I]], [[MUL4_I]]
; CHECK-NEXT: [[ADD_I:%.*]] = fadd float [[SUB_I]], [[TMP0]]
; CHECK-NEXT: [[INC]] = add nuw nsw i32 [[I_0]], 1
-; CHECK-NEXT: [[BIT0:%.*]] = and i32 [[INC]], 1
-; CHECK-NEXT: [[EVEN_NOT_NOT:%.*]] = icmp eq i32 [[BIT0]], 0
-; CHECK-NEXT: br i1 [[EVEN_NOT_NOT]], label [[EVEN_BB:%.*]], label [[ODD_BB]]
+; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[I_0]], 1
+; CHECK-NEXT: [[EVEN_NOT_NOT_NOT:%.*]] = icmp eq i32 [[TMP5]], 0
+; CHECK-NEXT: br i1 [[EVEN_NOT_NOT_NOT]], label [[ODD_BB]], label [[EVEN_BB:%.*]]
; CHECK: even.bb:
-; CHECK-NEXT: [[TMP5:%.*]] = fadd float [[SUB_I]], [[ADD_I]]
+; CHECK-NEXT: [[TMP6:%.*]] = fadd float [[SUB_I]], [[ADD_I]]
; CHECK-NEXT: br label [[ODD_BB]]
; CHECK: odd.bb:
-; CHECK-NEXT: [[TMP6]] = phi float [ [[ADD_I]], [[FOR_BODY]] ], [ [[TMP5]], [[EVEN_BB]] ]
+; CHECK-NEXT: [[TMP7]] = phi float [ [[ADD_I]], [[FOR_BODY]] ], [ [[TMP6]], [[EVEN_BB]] ]
; CHECK-NEXT: br label [[FOR_COND]]
; CHECK: for.end:
; CHECK-NEXT: store float [[TMP0]], ptr @dd, align 4
diff --git a/llvm/test/Transforms/PGOProfile/cspgo_profile_summary.ll b/llvm/test/Transforms/PGOProfile/cspgo_profile_summary.ll
index b4a27ee65613365..7040bac6a4c43f0 100644
--- a/llvm/test/Transforms/PGOProfile/cspgo_profile_summary.ll
+++ b/llvm/test/Transforms/PGOProfile/cspgo_profile_summary.ll
@@ -104,7 +104,7 @@ for.end:
; CSPGOSUMMARY-LABEL: @foo
; CSPGOSUMMARY: %even.odd.i = select i1 %tobool.i{{[0-9]*}}, ptr @even, ptr @odd
; CSPGOSUMMARY-SAME: !prof ![[BW_CSPGO_BAR]]
-; CSPGOSUMMARY: %even.odd.i2 = select i1 %tobool.i{{[0-9]*}}, ptr @even, ptr @odd
+; CSPGOSUMMARY: %even.odd.i2 = select i1 %tobool.i{{[0-9]*}}, ptr @odd, ptr @even
; CSPGOSUMMARY-SAME: !prof ![[BW_CSPGO_BAR]]
declare dso_local i32 @bar_m(i32)
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