b8f3024a31
Since all optimizations that use range metadata now also handle range attribute, this patch replaces writes of range metadata for call instructions to range attributes.
38 lines
1.2 KiB
LLVM
38 lines
1.2 KiB
LLVM
;; This tests lowering of the implementations of table-based ctz
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;; algorithm to the llvm.cttz instruction in the -O3 case.
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;; C producer:
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;; int ctz1 (unsigned x)
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;; {
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;; static const char table[32] =
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;; {
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;; 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
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;; 31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
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;; };
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;; return table[((unsigned)((x & -x) * 0x077CB531U)) >> 27];
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;; }
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;; Compiled as: clang -O3 test.c -S -emit-llvm -Xclang -disable-llvm-optzns
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; RUN: opt -O3 -S < %s | FileCheck %s
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; CHECK: call range(i32 0, 33) i32 @llvm.cttz.i32
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@ctz1.table = internal constant [32 x i8] c"\00\01\1C\02\1D\0E\18\03\1E\16\14\0F\19\11\04\08\1F\1B\0D\17\15\13\10\07\1A\0C\12\06\0B\05\0A\09", align 16
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define i32 @ctz1(i32 noundef %x) {
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entry:
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%x.addr = alloca i32, align 4
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store i32 %x, ptr %x.addr, align 4
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%0 = load i32, ptr %x.addr, align 4
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%1 = load i32, ptr %x.addr, align 4
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%sub = sub i32 0, %1
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%and = and i32 %0, %sub
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%mul = mul i32 %and, 125613361
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%shr = lshr i32 %mul, 27
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%idxprom = zext i32 %shr to i64
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%arrayidx = getelementptr inbounds [32 x i8], ptr @ctz1.table, i64 0, i64 %idxprom
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%2 = load i8, ptr %arrayidx, align 1
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%conv = sext i8 %2 to i32
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ret i32 %conv
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}
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