[llvm] Reapply "[LICM] Fold associative binary ops to promote code hoisting (#81608)" (PR #100377)
via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 24 06:50:20 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-llvm-transforms
Author: Ricardo Jesus (rj-jesus)
<details>
<summary>Changes</summary>
This reverts commit https://github.com/llvm/llvm-project/commit/b48819dbcdb48fc737dc22304ac343e4fdbae9ff.
This reapplies a more strict version of https://github.com/llvm/llvm-project/commit/f2ccf80136a01ca69f766becafb329db6c54c0c8.
Perform the transformation
"(LV op C1) op C2" ==> "LV op (C1 op C2)"
where op is an associative binary op, LV is a loop variant, and C1 and C2 are loop invariants, and hoist (C1 op C2) into the preheader.
For now this fold is restricted to ADDs.
---
Patch is 27.28 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/100377.diff
4 Files Affected:
- (modified) llvm/lib/Transforms/Scalar/LICM.cpp (+74)
- (modified) llvm/test/CodeGen/PowerPC/common-chain.ll (+160-155)
- (added) llvm/test/Transforms/LICM/hoist-binop.ll (+229)
- (modified) llvm/test/Transforms/LICM/sink-foldable.ll (+3-2)
``````````diff
diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index 91ef2b4b7c183..fe29fc36e2bb2 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -113,6 +113,8 @@ STATISTIC(NumFPAssociationsHoisted, "Number of invariant FP expressions "
STATISTIC(NumIntAssociationsHoisted,
"Number of invariant int expressions "
"reassociated and hoisted out of the loop");
+STATISTIC(NumBOAssociationsHoisted, "Number of invariant BinaryOp expressions "
+ "reassociated and hoisted out of the loop");
/// Memory promotion is enabled by default.
static cl::opt<bool>
@@ -2779,6 +2781,72 @@ static bool hoistMulAddAssociation(Instruction &I, Loop &L,
return true;
}
+/// Reassociate associative binary expressions of the form
+///
+/// 1. "(LV op C1) op C2" ==> "LV op (C1 op C2)"
+///
+/// where op is an associative binary op, LV is a loop variant, and C1 and C2
+/// are loop invariants that we want to hoist.
+///
+/// TODO: This can be extended to more cases such as
+/// 2. "C1 op (C2 op LV)" ==> "(C1 op C2) op LV"
+/// 3. "(C1 op LV) op C2" ==> "LV op (C1 op C2)" if op is commutative
+/// 4. "C1 op (LV op C2)" ==> "(C1 op C2) op LV" if op is commutative
+static bool hoistBOAssociation(Instruction &I, Loop &L,
+ ICFLoopSafetyInfo &SafetyInfo,
+ MemorySSAUpdater &MSSAU, AssumptionCache *AC,
+ DominatorTree *DT) {
+ BinaryOperator *BO = dyn_cast<BinaryOperator>(&I);
+ if (!BO || !BO->isAssociative())
+ return false;
+
+ // Only fold ADDs for now.
+ Instruction::BinaryOps Opcode = BO->getOpcode();
+ if (Opcode != Instruction::Add)
+ return false;
+
+ BinaryOperator *BO0 = dyn_cast<BinaryOperator>(BO->getOperand(0));
+
+ // Transform: "(LV op C1) op C2" ==> "LV op (C1 op C2)"
+ if (BO0 && BO0->getOpcode() == Opcode && BO0->isAssociative()) {
+ Value *LV = BO0->getOperand(0);
+ Value *C1 = BO0->getOperand(1);
+ Value *C2 = BO->getOperand(1);
+
+ if (L.isLoopInvariant(LV) || !L.isLoopInvariant(C1) ||
+ !L.isLoopInvariant(C2))
+ return false;
+
+ auto *Preheader = L.getLoopPreheader();
+ assert(Preheader && "Loop is not in simplify form?");
+
+ auto *Inv = BinaryOperator::Create(Opcode, C1, C2, "invariant.op",
+ Preheader->getTerminator());
+ auto *NewBO = BinaryOperator::Create(Opcode, LV, Inv,
+ BO->getName() + ".reass", BO);
+
+ // Copy NUW for ADDs if both instructions have it.
+ // https://alive2.llvm.org/ce/z/K9W3rk
+ if (Opcode == Instruction::Add && BO->hasNoUnsignedWrap() &&
+ BO0->hasNoUnsignedWrap()) {
+ Inv->setHasNoUnsignedWrap(true);
+ NewBO->setHasNoUnsignedWrap(true);
+ }
+
+ BO->replaceAllUsesWith(NewBO);
+ eraseInstruction(*BO, SafetyInfo, MSSAU);
+
+ // Note: (LV op C1) might not be erased if it has more uses than the one we
+ // just replaced.
+ if (BO0->use_empty())
+ eraseInstruction(*BO0, SafetyInfo, MSSAU);
+
+ return true;
+ }
+
+ return false;
+}
+
static bool hoistArithmetics(Instruction &I, Loop &L,
ICFLoopSafetyInfo &SafetyInfo,
MemorySSAUpdater &MSSAU, AssumptionCache *AC,
@@ -2816,6 +2884,12 @@ static bool hoistArithmetics(Instruction &I, Loop &L,
return true;
}
+ if (hoistBOAssociation(I, L, SafetyInfo, MSSAU, AC, DT)) {
+ ++NumHoisted;
+ ++NumBOAssociationsHoisted;
+ return true;
+ }
+
return false;
}
diff --git a/llvm/test/CodeGen/PowerPC/common-chain.ll b/llvm/test/CodeGen/PowerPC/common-chain.ll
index 5f8c21e30f8fd..ccf0e4520f468 100644
--- a/llvm/test/CodeGen/PowerPC/common-chain.ll
+++ b/llvm/test/CodeGen/PowerPC/common-chain.ll
@@ -642,8 +642,8 @@ define i64 @two_chain_two_bases_succ(ptr %p, i64 %offset, i64 %base1, i64 %base2
; CHECK-NEXT: cmpdi r7, 0
; CHECK-NEXT: ble cr0, .LBB6_4
; CHECK-NEXT: # %bb.1: # %for.body.preheader
-; CHECK-NEXT: add r6, r6, r4
; CHECK-NEXT: add r5, r5, r4
+; CHECK-NEXT: add r6, r6, r4
; CHECK-NEXT: mtctr r7
; CHECK-NEXT: sldi r4, r4, 1
; CHECK-NEXT: add r5, r3, r5
@@ -743,214 +743,219 @@ define signext i32 @spill_reduce_succ(ptr %input1, ptr %input2, ptr %output, i64
; CHECK-NEXT: std r9, -184(r1) # 8-byte Folded Spill
; CHECK-NEXT: std r8, -176(r1) # 8-byte Folded Spill
; CHECK-NEXT: std r7, -168(r1) # 8-byte Folded Spill
-; CHECK-NEXT: std r3, -160(r1) # 8-byte Folded Spill
+; CHECK-NEXT: std r4, -160(r1) # 8-byte Folded Spill
; CHECK-NEXT: ble cr0, .LBB7_7
; CHECK-NEXT: # %bb.1: # %for.body.preheader
-; CHECK-NEXT: sldi r6, r6, 2
-; CHECK-NEXT: li r7, 1
-; CHECK-NEXT: mr r30, r10
-; CHECK-NEXT: cmpdi r6, 1
-; CHECK-NEXT: iselgt r7, r6, r7
-; CHECK-NEXT: addi r8, r7, -1
-; CHECK-NEXT: clrldi r6, r7, 63
-; CHECK-NEXT: cmpldi r8, 3
+; CHECK-NEXT: sldi r4, r6, 2
+; CHECK-NEXT: li r6, 1
+; CHECK-NEXT: mr r0, r10
+; CHECK-NEXT: std r10, -192(r1) # 8-byte Folded Spill
+; CHECK-NEXT: cmpdi r4, 1
+; CHECK-NEXT: iselgt r4, r4, r6
+; CHECK-NEXT: addi r7, r4, -1
+; CHECK-NEXT: clrldi r6, r4, 63
+; CHECK-NEXT: cmpldi r7, 3
; CHECK-NEXT: blt cr0, .LBB7_4
; CHECK-NEXT: # %bb.2: # %for.body.preheader.new
-; CHECK-NEXT: ld r14, -168(r1) # 8-byte Folded Reload
-; CHECK-NEXT: mulli r24, r30, 24
-; CHECK-NEXT: ld r16, -184(r1) # 8-byte Folded Reload
-; CHECK-NEXT: ld r15, -176(r1) # 8-byte Folded Reload
-; CHECK-NEXT: ld r3, -160(r1) # 8-byte Folded Reload
-; CHECK-NEXT: rldicl r0, r7, 62, 2
-; CHECK-NEXT: sldi r11, r30, 5
-; CHECK-NEXT: sldi r19, r30, 4
-; CHECK-NEXT: sldi r7, r14, 3
-; CHECK-NEXT: add r14, r30, r14
-; CHECK-NEXT: sldi r10, r16, 3
-; CHECK-NEXT: sldi r12, r15, 3
-; CHECK-NEXT: add r16, r30, r16
-; CHECK-NEXT: add r15, r30, r15
-; CHECK-NEXT: add r27, r11, r7
-; CHECK-NEXT: add r22, r24, r7
-; CHECK-NEXT: add r17, r19, r7
-; CHECK-NEXT: sldi r2, r14, 3
-; CHECK-NEXT: add r26, r24, r10
-; CHECK-NEXT: add r25, r24, r12
-; CHECK-NEXT: add r21, r19, r10
-; CHECK-NEXT: add r20, r19, r12
-; CHECK-NEXT: add r8, r11, r10
-; CHECK-NEXT: sldi r16, r16, 3
-; CHECK-NEXT: add r29, r5, r27
-; CHECK-NEXT: add r28, r4, r27
-; CHECK-NEXT: add r27, r3, r27
-; CHECK-NEXT: add r24, r5, r22
-; CHECK-NEXT: add r23, r4, r22
-; CHECK-NEXT: add r22, r3, r22
-; CHECK-NEXT: add r19, r5, r17
-; CHECK-NEXT: add r18, r4, r17
-; CHECK-NEXT: add r17, r3, r17
-; CHECK-NEXT: add r14, r5, r2
-; CHECK-NEXT: add r31, r4, r2
-; CHECK-NEXT: add r2, r3, r2
-; CHECK-NEXT: add r9, r5, r8
-; CHECK-NEXT: add r8, r11, r12
+; CHECK-NEXT: ld r0, -192(r1) # 8-byte Folded Reload
+; CHECK-NEXT: ld r30, -184(r1) # 8-byte Folded Reload
+; CHECK-NEXT: ld r8, -176(r1) # 8-byte Folded Reload
+; CHECK-NEXT: rldicl r7, r4, 62, 2
+; CHECK-NEXT: ld r9, -168(r1) # 8-byte Folded Reload
+; CHECK-NEXT: add r11, r0, r30
+; CHECK-NEXT: add r4, r0, r0
+; CHECK-NEXT: mulli r23, r0, 24
+; CHECK-NEXT: add r14, r0, r8
+; CHECK-NEXT: sldi r12, r0, 5
+; CHECK-NEXT: add r31, r0, r9
+; CHECK-NEXT: sldi r9, r9, 3
+; CHECK-NEXT: sldi r18, r0, 4
+; CHECK-NEXT: sldi r8, r8, 3
+; CHECK-NEXT: add r10, r4, r4
+; CHECK-NEXT: sldi r4, r30, 3
+; CHECK-NEXT: sldi r11, r11, 3
+; CHECK-NEXT: add r26, r12, r9
+; CHECK-NEXT: add r16, r18, r9
+; CHECK-NEXT: add r29, r12, r8
+; CHECK-NEXT: add r19, r18, r8
+; CHECK-NEXT: add r30, r12, r4
+; CHECK-NEXT: mr r20, r4
+; CHECK-NEXT: std r4, -200(r1) # 8-byte Folded Spill
+; CHECK-NEXT: ld r4, -160(r1) # 8-byte Folded Reload
+; CHECK-NEXT: add r15, r5, r11
+; CHECK-NEXT: sldi r11, r14, 3
+; CHECK-NEXT: add r29, r5, r29
+; CHECK-NEXT: add r28, r3, r26
+; CHECK-NEXT: add r19, r5, r19
+; CHECK-NEXT: add r21, r23, r9
+; CHECK-NEXT: add r24, r23, r8
+; CHECK-NEXT: add r14, r5, r11
+; CHECK-NEXT: sldi r11, r31, 3
+; CHECK-NEXT: add r25, r23, r20
+; CHECK-NEXT: add r20, r18, r20
+; CHECK-NEXT: add r30, r5, r30
+; CHECK-NEXT: add r18, r3, r16
+; CHECK-NEXT: add r24, r5, r24
+; CHECK-NEXT: add r23, r3, r21
+; CHECK-NEXT: add r27, r4, r26
+; CHECK-NEXT: add r22, r4, r21
+; CHECK-NEXT: add r17, r4, r16
+; CHECK-NEXT: add r2, r4, r11
+; CHECK-NEXT: rldicl r4, r7, 2, 1
+; CHECK-NEXT: sub r7, r8, r9
+; CHECK-NEXT: ld r8, -200(r1) # 8-byte Folded Reload
; CHECK-NEXT: add r26, r5, r26
; CHECK-NEXT: add r25, r5, r25
; CHECK-NEXT: add r21, r5, r21
; CHECK-NEXT: add r20, r5, r20
; CHECK-NEXT: add r16, r5, r16
-; CHECK-NEXT: add r8, r5, r8
-; CHECK-NEXT: rldicl r3, r0, 2, 1
-; CHECK-NEXT: addi r3, r3, -4
-; CHECK-NEXT: sub r0, r12, r7
-; CHECK-NEXT: sub r12, r10, r7
-; CHECK-NEXT: li r7, 0
-; CHECK-NEXT: mr r10, r30
-; CHECK-NEXT: sldi r15, r15, 3
-; CHECK-NEXT: add r15, r5, r15
-; CHECK-NEXT: rldicl r3, r3, 62, 2
-; CHECK-NEXT: addi r3, r3, 1
-; CHECK-NEXT: mtctr r3
+; CHECK-NEXT: add r31, r5, r11
+; CHECK-NEXT: add r11, r3, r11
+; CHECK-NEXT: addi r4, r4, -4
+; CHECK-NEXT: rldicl r4, r4, 62, 2
+; CHECK-NEXT: sub r8, r8, r9
+; CHECK-NEXT: li r9, 0
+; CHECK-NEXT: addi r4, r4, 1
+; CHECK-NEXT: mtctr r4
; CHECK-NEXT: .p2align 4
; CHECK-NEXT: .LBB7_3: # %for.body
; CHECK-NEXT: #
-; CHECK-NEXT: lfd f0, 0(r2)
-; CHECK-NEXT: lfd f1, 0(r31)
-; CHECK-NEXT: add r3, r10, r30
-; CHECK-NEXT: add r3, r3, r30
+; CHECK-NEXT: lfd f0, 0(r11)
+; CHECK-NEXT: lfd f1, 0(r2)
+; CHECK-NEXT: add r0, r0, r10
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfd f1, 0(r14)
-; CHECK-NEXT: add r3, r3, r30
-; CHECK-NEXT: add r10, r3, r30
+; CHECK-NEXT: lfd f1, 0(r31)
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfd f0, 0(r14)
-; CHECK-NEXT: add r14, r14, r11
-; CHECK-NEXT: lfdx f0, r2, r0
-; CHECK-NEXT: lfdx f1, r31, r0
+; CHECK-NEXT: stfd f0, 0(r31)
+; CHECK-NEXT: add r31, r31, r12
+; CHECK-NEXT: lfdx f0, r11, r7
+; CHECK-NEXT: lfdx f1, r2, r7
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r15, r7
+; CHECK-NEXT: lfdx f1, r14, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r15, r7
-; CHECK-NEXT: lfdx f0, r2, r12
-; CHECK-NEXT: lfdx f1, r31, r12
-; CHECK-NEXT: add r2, r2, r11
-; CHECK-NEXT: add r31, r31, r11
+; CHECK-NEXT: stfdx f0, r14, r9
+; CHECK-NEXT: lfdx f0, r11, r8
+; CHECK-NEXT: lfdx f1, r2, r8
+; CHECK-NEXT: add r11, r11, r12
+; CHECK-NEXT: add r2, r2, r12
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r16, r7
+; CHECK-NEXT: lfdx f1, r15, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r16, r7
-; CHECK-NEXT: lfd f0, 0(r17)
-; CHECK-NEXT: lfd f1, 0(r18)
+; CHECK-NEXT: stfdx f0, r15, r9
+; CHECK-NEXT: lfd f0, 0(r18)
+; CHECK-NEXT: lfd f1, 0(r17)
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r19, r7
+; CHECK-NEXT: lfdx f1, r16, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r19, r7
-; CHECK-NEXT: lfdx f0, r17, r0
-; CHECK-NEXT: lfdx f1, r18, r0
+; CHECK-NEXT: stfdx f0, r16, r9
+; CHECK-NEXT: lfdx f0, r18, r7
+; CHECK-NEXT: lfdx f1, r17, r7
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r20, r7
+; CHECK-NEXT: lfdx f1, r19, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r20, r7
-; CHECK-NEXT: lfdx f0, r17, r12
-; CHECK-NEXT: lfdx f1, r18, r12
-; CHECK-NEXT: add r17, r17, r11
-; CHECK-NEXT: add r18, r18, r11
+; CHECK-NEXT: stfdx f0, r19, r9
+; CHECK-NEXT: lfdx f0, r18, r8
+; CHECK-NEXT: lfdx f1, r17, r8
+; CHECK-NEXT: add r18, r18, r12
+; CHECK-NEXT: add r17, r17, r12
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r21, r7
+; CHECK-NEXT: lfdx f1, r20, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r21, r7
-; CHECK-NEXT: lfd f0, 0(r22)
-; CHECK-NEXT: lfd f1, 0(r23)
+; CHECK-NEXT: stfdx f0, r20, r9
+; CHECK-NEXT: lfd f0, 0(r23)
+; CHECK-NEXT: lfd f1, 0(r22)
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r24, r7
+; CHECK-NEXT: lfdx f1, r21, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r24, r7
-; CHECK-NEXT: lfdx f0, r22, r0
-; CHECK-NEXT: lfdx f1, r23, r0
+; CHECK-NEXT: stfdx f0, r21, r9
+; CHECK-NEXT: lfdx f0, r23, r7
+; CHECK-NEXT: lfdx f1, r22, r7
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r25, r7
+; CHECK-NEXT: lfdx f1, r24, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r25, r7
-; CHECK-NEXT: lfdx f0, r22, r12
-; CHECK-NEXT: lfdx f1, r23, r12
-; CHECK-NEXT: add r22, r22, r11
-; CHECK-NEXT: add r23, r23, r11
+; CHECK-NEXT: stfdx f0, r24, r9
+; CHECK-NEXT: lfdx f0, r23, r8
+; CHECK-NEXT: lfdx f1, r22, r8
+; CHECK-NEXT: add r23, r23, r12
+; CHECK-NEXT: add r22, r22, r12
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r26, r7
+; CHECK-NEXT: lfdx f1, r25, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r26, r7
-; CHECK-NEXT: lfd f0, 0(r27)
-; CHECK-NEXT: lfd f1, 0(r28)
+; CHECK-NEXT: stfdx f0, r25, r9
+; CHECK-NEXT: lfd f0, 0(r28)
+; CHECK-NEXT: lfd f1, 0(r27)
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r29, r7
+; CHECK-NEXT: lfdx f1, r26, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r29, r7
-; CHECK-NEXT: lfdx f0, r27, r0
-; CHECK-NEXT: lfdx f1, r28, r0
+; CHECK-NEXT: stfdx f0, r26, r9
+; CHECK-NEXT: lfdx f0, r28, r7
+; CHECK-NEXT: lfdx f1, r27, r7
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r8, r7
+; CHECK-NEXT: lfdx f1, r29, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r8, r7
-; CHECK-NEXT: lfdx f0, r27, r12
-; CHECK-NEXT: lfdx f1, r28, r12
-; CHECK-NEXT: add r27, r27, r11
-; CHECK-NEXT: add r28, r28, r11
+; CHECK-NEXT: stfdx f0, r29, r9
+; CHECK-NEXT: lfdx f0, r28, r8
+; CHECK-NEXT: lfdx f1, r27, r8
+; CHECK-NEXT: add r28, r28, r12
+; CHECK-NEXT: add r27, r27, r12
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r9, r7
+; CHECK-NEXT: lfdx f1, r30, r9
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r9, r7
-; CHECK-NEXT: add r7, r7, r11
+; CHECK-NEXT: stfdx f0, r30, r9
+; CHECK-NEXT: add r9, r9, r12
; CHECK-NEXT: bdnz .LBB7_3
; CHECK-NEXT: .LBB7_4: # %for.cond.cleanup.loopexit.unr-lcssa
+; CHECK-NEXT: ld r7, -192(r1) # 8-byte Folded Reload
; CHECK-NEXT: cmpldi r6, 0
; CHECK-NEXT: beq cr0, .LBB7_7
; CHECK-NEXT: # %bb.5: # %for.body.epil.preheader
-; CHECK-NEXT: ld r3, -184(r1) # 8-byte Folded Reload
-; CHECK-NEXT: ld r0, -160(r1) # 8-byte Folded Reload
-; CHECK-NEXT: sldi r8, r30, 3
-; CHECK-NEXT: add r3, r10, r3
-; CHECK-NEXT: sldi r3, r3, 3
-; CHECK-NEXT: add r7, r5, r3
-; CHECK-NEXT: add r9, r4, r3
-; CHECK-NEXT: add r11, r0, r3
-; CHECK-NEXT: ld r3, -176(r1) # 8-byte Folded Reload
-; CHECK-NEXT: add r3, r10, r3
-; CHECK-NEXT: sldi r3, r3, 3
-; CHECK-NEXT: add r12, r5, r3
-; CHECK-NEXT: add r30, r4, r3
-; CHECK-NEXT: add r29, r0, r3
-; CHECK-NEXT: ld r3, -168(r1) # 8-byte Folded Reload
-; CHECK-NEXT: add r3, r10, r3
-; CHECK-NEXT: li r10, 0
-; CHECK-NEXT: sldi r3, r3, 3
-; CHECK-NEXT: add r5, r5, r3
-; CHECK-NEXT: add r4, r4, r3
-; CHECK-NEXT: add r3, r0, r3
+; CHECK-NEXT: ld r4, -184(r1) # 8-byte Folded Reload
+; CHECK-NEXT: ld r29, -160(r1) # 8-byte Folded Reload
+; CHECK-NEXT: mr r30, r3
+; CHECK-NEXT: sldi r7, r7, 3
+; CHECK-NEXT: add r4, r0, r4
+; CHECK-NEXT: sldi r4, r4, 3
+; CHECK-NEXT: add r3, r5, r4
+; CHECK-NEXT: add r8, r29, r4
+; CHECK-NEXT: add r9, r30, r4
+; CHECK-NEXT: ld r4, -176(r1) # 8-byte Folded Reload
+; CHECK-NEXT: add r4, r0, r4
+; CHECK-NEXT: sldi r4, r4, 3
+; CHECK-NEXT: add r10, r5, r4
+; CHECK-NEXT: add r11, r29, r4
+; CHECK-NEXT: add r12, r30, r4
+; CHECK-NEXT: ld r4, -168(r1) # 8-byte Folded Reload
+; CHECK-NEXT: add r4, r0, r4
+; CHECK-NEXT: sldi r0, r4, 3
+; CHECK-NEXT: add r5, r5, r0
+; CHECK-NEXT: add r4, r29, r0
+; CHECK-NEXT: add r30, r30, r0
+; CHECK-NEXT: li r0, 0
; CHECK-NEXT: .p2align 4
; CHECK-NEXT: .LBB7_6: # %for.body.epil
; CHECK-NEXT: #
-; CHECK-NEXT: lfdx f0, r3, r10
-; CHECK-NEXT: lfdx f1, r4, r10
+; CHECK-NEXT: lfdx f0, r30, r0
+; CHECK-NEXT: lfdx f1, r4, r0
; CHECK-NEXT: addi r6, r6, -1
; CHECK-NEXT: cmpldi r6, 0
; CHECK-NEXT: xsmuldp f0, f0, f1
; CHECK-NEXT: lfd f1, 0(r5)
; CHECK-NEXT: xsadddp f0, f1, f0
; CHECK-NEXT: stfd f0, 0(r5)
-; CHECK-NEXT: add r5, r5, r8
-; CHECK-NEXT: lfdx f0, r29, r10
-; CHECK-NEXT: lfdx f1, r30, r10
+; CHECK-NEXT: add r5, r5, r7
+; CHECK-NEXT: lfdx f0, r12, r0
+; CHECK-NEXT: lfdx f1, r11, r0
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r12, r10
+; CHECK-NEXT: lfdx f1, r10, r0
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r12, r10
-; CHECK-NEXT: lfdx f0, r11, r10
-; CHECK-NEXT: lfdx f1, r9, r10
+; CHECK-NEXT: stfdx f0, r10, r0
+; CHECK-NEXT: lfdx f0, r9, r0
+; CHECK-NEXT: lfdx f1, r8, r0
; CHECK-NEXT: xsmuldp f0, f0, f1
-; CHECK-NEXT: lfdx f1, r7, r10
+; CHECK-NEXT: lfdx f1, r3, r0
; CHECK-NEXT: xsadddp f0, f1, f0
-; CHECK-NEXT: stfdx f0, r7, r10
-; CHECK-NEXT: add r10, r10, r8
+; CHECK-NEXT: stfdx f0, r3, r0
+; CHECK-NEXT: add r0, r0, r7
; CHECK-NEXT: bne cr0, .LBB7_6
; CHECK-NEXT: .LBB7_7: # %for.cond.cleanup
; CHECK-NEXT: ld r2, -152(r1) # 8-byte Folded Reload
diff --git a/llvm/test/Transforms/LICM/hoist-binop.ll b/llvm/test/Transforms/LICM/hoist-binop.ll
new file mode 100644
index 0000000000000..9cdcc359c61ab
--- /dev/null
+++ b/llvm/test/Transforms/LICM/hoist-binop.ll
@@ -0,0 +1,229 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -passes=licm < %s | FileCheck %s
+
+; Fold ADD and remove old op if unused.
+; https://alive2.llvm.org/ce/z/wAY-Nd
+define void @add_one_use(i64 %c) {
+; CHECK-LABEL: @add_one_use(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[INVARIANT_OP:%.*]] = add i64 [[C:%.*]], [[C]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[INDEX_NEXT_REASS:%.*]], [[LOOP]] ]
+; CHECK-NEXT: [[INDEX_NEXT_REASS]] = add i64 [[INDEX]], [[INVARIANT_OP]]
+; CHECK-NEXT: br label [[LOOP]]
+;
+entry:
+ br label %loop
+
+loop:
+ %index = phi i64 [ 0, %entry ], [ %index.next, %loop ]
+ %step.add = add i64 %index, %c
+ %index.next = add i64 %step.add, %c
+ br label %loop
+}
+
+; Fold ADD and copy NUW if both ops have it.
+; https://alive2.llvm.org/ce/z/wAY-Nd
+define void @add_nuw(i64 %c) {
+; CHECK-LABEL: @add_nuw(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[INVARIANT_OP:%.*]] = add nuw i64 [[C:%.*]], [[C]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[INDEX_NEXT_REASS:%.*]], [[LOOP]] ]
+; CHECK-NEXT: [[STEP_ADD:%.*]] = add nuw i64 [[INDEX]], [[C]]
+; CHECK-NEXT: call void @use(i64 [[STEP_ADD]])
+; CHECK-NEXT: [[INDEX_NEXT_REASS]] = add nuw i64 [[INDEX]], [[INVARIANT_OP]]
+; CHECK-NEXT: br label [[LOOP]]
+;
+entry:
+ br label %loop
+
+loop:
+ %index = phi i64 [ 0, %entry ], [ %index.next, %loop ]
+ %step.add = add nuw i64 %index, %c
+ call void @use(i64 %step.add)
+ %index.next = add nuw i64 %step.add, %c
+ br label %loop
+}
+
+; Fold ADD but don't copy NUW if only one op has it.
+; https://alive2.llvm.org/ce/z/6n95Gf
+define void @add_no_nuw(i64 %c) {
+; CHECK-LABEL: @add_no_nuw(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[INVARIANT_OP:%.*]] = add i64 [[C:%.*]], [[C]]
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[INDEX_NEXT_REASS:%.*]], [[LOOP]] ]
+; CHECK-NEXT: [[STEP_ADD:%.*]] = add i64 [[INDEX]], [[C]]
+; CHECK-NEXT: call void @use(i64 [[STEP_ADD]])
+; CHECK-NEXT: [[INDEX_NEXT_REASS...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/100377
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