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590884a860
Now that `align_{up,down}` use `llvm.ptrmask` (as of #71238), the
assume doesn't preserve any information that is not still easily
re-computable.
Closes #71295
51 lines
2.7 KiB
C
51 lines
2.7 KiB
C
// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
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/// Check that the alignment builtins handle array-to-pointer decay
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// RUN: %clang_cc1 -triple=x86_64-unknown-unknown -o - -emit-llvm %s | FileCheck %s
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extern int func(char *c);
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// CHECK-LABEL: @test_array(
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// CHECK-NEXT: entry:
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// CHECK-NEXT: [[BUF:%.*]] = alloca [1024 x i8], align 16
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// CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 44
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// CHECK-NEXT: [[ALIGNED_RESULT:%.*]] = call ptr @llvm.ptrmask.p0.i64(ptr [[ARRAYIDX]], i64 -16)
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// CHECK-NEXT: [[CALL:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT]])
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// CHECK-NEXT: [[ARRAYIDX1:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 22
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// CHECK-NEXT: [[OVER_BOUNDARY:%.*]] = getelementptr inbounds i8, ptr [[ARRAYIDX1]], i64 31
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// CHECK-NEXT: [[ALIGNED_RESULT2:%.*]] = call ptr @llvm.ptrmask.p0.i64(ptr [[OVER_BOUNDARY]], i64 -32)
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// CHECK-NEXT: [[CALL3:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT2]])
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// CHECK-NEXT: [[ARRAYIDX4:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 16
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// CHECK-NEXT: [[SRC_ADDR:%.*]] = ptrtoint ptr [[ARRAYIDX4]] to i64
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// CHECK-NEXT: [[SET_BITS:%.*]] = and i64 [[SRC_ADDR]], 63
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// CHECK-NEXT: [[IS_ALIGNED:%.*]] = icmp eq i64 [[SET_BITS]], 0
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// CHECK-NEXT: [[CONV:%.*]] = zext i1 [[IS_ALIGNED]] to i32
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// CHECK-NEXT: ret i32 [[CONV]]
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//
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int test_array(void) {
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char buf[1024];
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func(__builtin_align_down(&buf[44], 16));
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func(__builtin_align_up(&buf[22], 32));
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return __builtin_is_aligned(&buf[16], 64);
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}
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// CHECK-LABEL: @test_array_should_not_mask(
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// CHECK-NEXT: entry:
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// CHECK-NEXT: [[BUF:%.*]] = alloca [1024 x i8], align 32
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// CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 64
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// CHECK-NEXT: [[ALIGNED_RESULT:%.*]] = call ptr @llvm.ptrmask.p0.i64(ptr [[ARRAYIDX]], i64 -16)
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// CHECK-NEXT: [[CALL:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT]])
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// CHECK-NEXT: [[ARRAYIDX1:%.*]] = getelementptr inbounds [1024 x i8], ptr [[BUF]], i64 0, i64 32
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// CHECK-NEXT: [[OVER_BOUNDARY:%.*]] = getelementptr inbounds i8, ptr [[ARRAYIDX1]], i64 31
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// CHECK-NEXT: [[ALIGNED_RESULT2:%.*]] = call ptr @llvm.ptrmask.p0.i64(ptr [[OVER_BOUNDARY]], i64 -32)
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// CHECK-NEXT: [[CALL3:%.*]] = call i32 @func(ptr noundef [[ALIGNED_RESULT2]])
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// CHECK-NEXT: ret i32 1
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//
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int test_array_should_not_mask(void) {
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_Alignas(32) char buf[1024];
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// TODO: The align_up and align_down calls should be folded to no-ops
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func(__builtin_align_down(&buf[64], 16));
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func(__builtin_align_up(&buf[32], 32));
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// This expression can be constant-evaluated:
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return __builtin_is_aligned(&buf[64], 32);
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}
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