c23b4fbdbb
Now that #149310 has restricted lifetime intrinsics to only work on allocas, we can also drop the explicit size argument. Instead, the size is implied by the alloca. This removes the ability to only mark a prefix of an alloca alive/dead. We never used that capability, so we should remove the need to handle that possibility everywhere (though many key places, including stack coloring, did not actually respect this).
137 lines
4.7 KiB
LLVM
137 lines
4.7 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt -passes="default<O3>" -rotation-max-header-size=0 -S < %s | FileCheck %s --check-prefix=HOIST
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; RUN: opt -passes="default<O3>" -rotation-max-header-size=1 -S < %s | FileCheck %s --check-prefix=HOIST
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; RUN: opt -passes="default<O3>" -rotation-max-header-size=2 -S < %s | FileCheck %s --check-prefix=ROTATE
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; RUN: opt -passes="default<O3>" -rotation-max-header-size=3 -S < %s | FileCheck %s --check-prefix=ROTATE
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; This example is produced from a very basic C code:
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;
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; void f0();
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; void f1();
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; void f2();
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;
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; void loop(int width) {
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; if(width < 1)
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; return;
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; for(int i = 0; i < width - 1; ++i) {
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; f0();
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; f1();
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; }
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; f0();
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; f2();
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; }
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; We have a choice here. We can either
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; * hoist the f0() call into loop header,
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; * which potentially makes loop rotation unprofitable since loop header might
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; have grown above certain threshold, and such unrotated loops will be
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; ignored by LoopVectorizer, preventing vectorization
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; * or loop rotation will succeed, resulting in some weird PHIs that will also
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; harm vectorization
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; * or not hoist f0() call before performing loop rotation,
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; at the cost of potential code bloat and/or potentially successfully rotating
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; the loops, vectorizing them at the cost of compile time.
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target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
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declare void @f0()
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declare void @f1()
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declare void @f2()
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declare void @llvm.lifetime.start.p0(ptr nocapture)
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declare void @llvm.lifetime.end.p0(ptr nocapture)
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define void @_Z4loopi(i32 %width) {
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; HOIST-LABEL: @_Z4loopi(
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; HOIST-NEXT: entry:
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; HOIST-NEXT: [[CMP:%.*]] = icmp slt i32 [[WIDTH:%.*]], 1
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; HOIST-NEXT: br i1 [[CMP]], label [[RETURN:%.*]], label [[FOR_COND_PREHEADER:%.*]]
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; HOIST: for.cond.preheader:
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; HOIST-NEXT: [[SUB:%.*]] = add nsw i32 [[WIDTH]], -1
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; HOIST-NEXT: br label [[FOR_COND:%.*]]
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; HOIST: for.cond:
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; HOIST-NEXT: [[I_0:%.*]] = phi i32 [ [[INC:%.*]], [[FOR_BODY:%.*]] ], [ 0, [[FOR_COND_PREHEADER]] ]
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; HOIST-NEXT: [[EXITCOND_NOT:%.*]] = icmp eq i32 [[I_0]], [[SUB]]
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; HOIST-NEXT: tail call void @f0()
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; HOIST-NEXT: br i1 [[EXITCOND_NOT]], label [[FOR_COND_CLEANUP:%.*]], label [[FOR_BODY]]
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; HOIST: for.cond.cleanup:
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; HOIST-NEXT: tail call void @f2()
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; HOIST-NEXT: br label [[RETURN]]
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; HOIST: for.body:
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; HOIST-NEXT: tail call void @f1()
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; HOIST-NEXT: [[INC]] = add nuw i32 [[I_0]], 1
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; HOIST-NEXT: br label [[FOR_COND]]
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; HOIST: return:
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; HOIST-NEXT: ret void
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;
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; ROTATE-LABEL: @_Z4loopi(
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; ROTATE-NEXT: entry:
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; ROTATE-NEXT: [[CMP:%.*]] = icmp slt i32 [[WIDTH:%.*]], 1
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; ROTATE-NEXT: br i1 [[CMP]], label [[RETURN:%.*]], label [[FOR_COND_PREHEADER:%.*]]
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; ROTATE: for.cond.preheader:
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; ROTATE-NEXT: [[CMP13_NOT:%.*]] = icmp eq i32 [[WIDTH]], 1
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; ROTATE-NEXT: br i1 [[CMP13_NOT]], label [[FOR_COND_CLEANUP:%.*]], label [[FOR_BODY_PREHEADER:%.*]]
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; ROTATE: for.body.preheader:
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; ROTATE-NEXT: [[TMP0:%.*]] = add nsw i32 [[WIDTH]], -2
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; ROTATE-NEXT: br label [[FOR_BODY:%.*]]
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; ROTATE: for.cond.cleanup:
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; ROTATE-NEXT: tail call void @f0()
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; ROTATE-NEXT: tail call void @f2()
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; ROTATE-NEXT: br label [[RETURN]]
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; ROTATE: for.body:
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; ROTATE-NEXT: [[I_04:%.*]] = phi i32 [ [[INC:%.*]], [[FOR_BODY]] ], [ 0, [[FOR_BODY_PREHEADER]] ]
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; ROTATE-NEXT: tail call void @f0()
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; ROTATE-NEXT: tail call void @f1()
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; ROTATE-NEXT: [[INC]] = add nuw nsw i32 [[I_04]], 1
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; ROTATE-NEXT: [[EXITCOND_NOT:%.*]] = icmp eq i32 [[I_04]], [[TMP0]]
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; ROTATE-NEXT: br i1 [[EXITCOND_NOT]], label [[FOR_COND_CLEANUP]], label [[FOR_BODY]]
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; ROTATE: return:
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; ROTATE-NEXT: ret void
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;
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entry:
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%width.addr = alloca i32, align 4
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%i = alloca i32, align 4
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store i32 %width, ptr %width.addr, align 4
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%i1 = load i32, ptr %width.addr, align 4
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%cmp = icmp slt i32 %i1, 1
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br i1 %cmp, label %if.then, label %if.end
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if.then:
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br label %return
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if.end:
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call void @llvm.lifetime.start.p0(ptr %i)
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store i32 0, ptr %i, align 4
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br label %for.cond
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for.cond:
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%i3 = load i32, ptr %i, align 4
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%i4 = load i32, ptr %width.addr, align 4
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%sub = sub nsw i32 %i4, 1
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%cmp1 = icmp slt i32 %i3, %sub
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br i1 %cmp1, label %for.body, label %for.cond.cleanup
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for.cond.cleanup:
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call void @llvm.lifetime.end.p0(ptr %i)
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br label %for.end
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for.body:
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call void @f0()
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call void @f1()
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br label %for.inc
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for.inc:
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%i6 = load i32, ptr %i, align 4
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%inc = add nsw i32 %i6, 1
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store i32 %inc, ptr %i, align 4
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br label %for.cond
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for.end:
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call void @f0()
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call void @f2()
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br label %return
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return:
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ret void
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}
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