78 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			78 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: llc < %s -march=x86-64 -mcpu=bdver1 | FileCheck %s
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; Verify that for the architectures that are known to have poor latency
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; double precision shift instructions we generate alternative sequence 
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; of instructions with lower latencies instead of shld instruction.
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;uint64_t lshift1(uint64_t a, uint64_t b)
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;{
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;    return (a << 1) | (b >> 63);
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;}
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; CHECK:             lshift1:
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; CHECK:             addq    {{.*}},{{.*}}
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; CHECK-NEXT:        shrq    $63, {{.*}}
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; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
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define i64 @lshift1(i64 %a, i64 %b) nounwind readnone uwtable {
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entry:
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  %shl = shl i64 %a, 1
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  %shr = lshr i64 %b, 63
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  %or = or i64 %shr, %shl
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  ret i64 %or
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}
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;uint64_t lshift2(uint64_t a, uint64_t b)
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;{
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;    return (a << 2) | (b >> 62);
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;}
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; CHECK:             lshift2:
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; CHECK:             shlq    $2, {{.*}}
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; CHECK-NEXT:        shrq    $62, {{.*}}
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; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
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define i64 @lshift2(i64 %a, i64 %b) nounwind readnone uwtable {
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entry:
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  %shl = shl i64 %a, 2
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  %shr = lshr i64 %b, 62
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  %or = or i64 %shr, %shl
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  ret i64 %or
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}
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;uint64_t lshift7(uint64_t a, uint64_t b)
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;{
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;    return (a << 7) | (b >> 57);
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;}
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; CHECK:             lshift7:
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; CHECK:             shlq    $7, {{.*}}
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; CHECK-NEXT:        shrq    $57, {{.*}}
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; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
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define i64 @lshift7(i64 %a, i64 %b) nounwind readnone uwtable {
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entry:
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  %shl = shl i64 %a, 7
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  %shr = lshr i64 %b, 57
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  %or = or i64 %shr, %shl
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  ret i64 %or
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}
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;uint64_t lshift63(uint64_t a, uint64_t b)
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;{
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;    return (a << 63) | (b >> 1);
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;}
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; CHECK:             lshift63:
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; CHECK:             shlq    $63, {{.*}}
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; CHECK-NEXT:        shrq    {{.*}}
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; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
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define i64 @lshift63(i64 %a, i64 %b) nounwind readnone uwtable {
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entry:
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  %shl = shl i64 %a, 63
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  %shr = lshr i64 %b, 1
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  %or = or i64 %shr, %shl
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  ret i64 %or
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}
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