[PATCH] D155073: [LSR] Don't consider users of constant outside loop

[Nikita Popov via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGddb46abd3c8b: [LSR] Don't consider users of constant outside loop (authored by nikic).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D155073/new/

https://reviews.llvm.org/D155073

Files:
  llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
  llvm/test/Transforms/LoopStrengthReduce/AArch64/lsr-memcpy.ll


Index: llvm/test/Transforms/LoopStrengthReduce/AArch64/lsr-memcpy.ll
===================================================================
--- llvm/test/Transforms/LoopStrengthReduce/AArch64/lsr-memcpy.ll
+++ llvm/test/Transforms/LoopStrengthReduce/AArch64/lsr-memcpy.ll
@@ -7,21 +7,18 @@
 ; <rdar://problem/12702735> [ARM64][coalescer] need better register
 ; coalescing for simple unit tests.
 
-; FIXME: This regressed after enabling opaque pointers.
 define i32 @test_inttoptr() nounwind {
 ; CHECK-LABEL: test_inttoptr:
 ; CHECK:       // %bb.0: // %entry
 ; CHECK-NEXT:    str x30, [sp, #-16]! // 8-byte Folded Spill
-; CHECK-NEXT:    mov x8, #0 // =0x0
-; CHECK-NEXT:    mov w9, #1288 // =0x508
-; CHECK-NEXT:    mov x10, #4294967296 // =0x100000000
-; CHECK-NEXT:    mov x11, #6442450944 // =0x180000000
+; CHECK-NEXT:    mov w8, #1288 // =0x508
+; CHECK-NEXT:    mov x9, #4294967296 // =0x100000000
+; CHECK-NEXT:    mov x10, #6442450944 // =0x180000000
 ; CHECK-NEXT:  .LBB0_1: // %while.body
 ; CHECK-NEXT:    // =>This Inner Loop Header: Depth=1
-; CHECK-NEXT:    ldr x12, [x8, x10]
-; CHECK-NEXT:    str x12, [x8, x11]
-; CHECK-NEXT:    add x8, x8, #8
-; CHECK-NEXT:    subs x9, x9, #8
+; CHECK-NEXT:    ldr x11, [x9], #8
+; CHECK-NEXT:    str x11, [x10], #8
+; CHECK-NEXT:    subs x8, x8, #8
 ; CHECK-NEXT:    b.pl .LBB0_1
 ; CHECK-NEXT:  // %bb.2: // %while.end
 ; CHECK-NEXT:    mov x8, #6442450944 // =0x180000000
@@ -55,18 +52,16 @@
 define ptr @test_globals() nounwind {
 ; CHECK-LABEL: test_globals:
 ; CHECK:       // %bb.0: // %entry
-; CHECK-NEXT:    mov x8, #0 // =0x0
-; CHECK-NEXT:    mov w9, #1288 // =0x508
-; CHECK-NEXT:    adrp x10, g2
-; CHECK-NEXT:    add x10, x10, :lo12:g2
-; CHECK-NEXT:    adrp x11, g1
-; CHECK-NEXT:    add x11, x11, :lo12:g1
+; CHECK-NEXT:    mov w8, #1288 // =0x508
+; CHECK-NEXT:    adrp x9, g2
+; CHECK-NEXT:    add x9, x9, :lo12:g2
+; CHECK-NEXT:    adrp x10, g1
+; CHECK-NEXT:    add x10, x10, :lo12:g1
 ; CHECK-NEXT:  .LBB1_1: // %while.body
 ; CHECK-NEXT:    // =>This Inner Loop Header: Depth=1
-; CHECK-NEXT:    ldr x12, [x10, x8]
-; CHECK-NEXT:    str x12, [x11, x8]
-; CHECK-NEXT:    add x8, x8, #8
-; CHECK-NEXT:    subs x9, x9, #8
+; CHECK-NEXT:    ldr x11, [x9], #8
+; CHECK-NEXT:    str x11, [x10], #8
+; CHECK-NEXT:    subs x8, x8, #8
 ; CHECK-NEXT:    b.pl .LBB1_1
 ; CHECK-NEXT:  // %bb.2: // %while.end
 ; CHECK-NEXT:    adrp x0, g1
Index: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -3507,8 +3507,8 @@
       if (const Instruction *Inst = dyn_cast<Instruction>(V)) {
         // Look for instructions defined outside the loop.
         if (L->contains(Inst)) continue;
-      } else if (isa<UndefValue>(V))
-        // Undef doesn't have a live range, so it doesn't matter.
+      } else if (isa<Constant>(V))
+        // Constants can be re-materialized.
         continue;
       for (const Use &U : V->uses()) {
         const Instruction *UserInst = dyn_cast<Instruction>(U.getUser());


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