75 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			75 lines
		
	
	
		
			1.8 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 shrd instruction.
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;uint64_t rshift1(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:             rshift1:
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; CHECK:             shrq    {{.*}}
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; CHECK-NEXT:        shlq    $63, {{.*}}
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; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
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define i64 @rshift1(i64 %a, i64 %b) nounwind readnone uwtable {
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  %1 = lshr i64 %a, 1
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  %2 = shl i64 %b, 63
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  %3 = or i64 %2, %1
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  ret i64 %3
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}
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;uint64_t rshift2(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:             rshift2:
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; CHECK:             shrq    $2, {{.*}}
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; CHECK-NEXT:        shlq    $62, {{.*}}
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; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
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define i64 @rshift2(i64 %a, i64 %b) nounwind readnone uwtable {
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  %1 = lshr i64 %a, 2
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  %2 = shl i64 %b, 62
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  %3 = or i64 %2, %1
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  ret i64 %3
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}
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;uint64_t rshift7(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:             rshift7:
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; CHECK:             shrq    $7, {{.*}}
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; CHECK-NEXT:        shlq    $57, {{.*}}
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; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
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define i64 @rshift7(i64 %a, i64 %b) nounwind readnone uwtable {
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  %1 = lshr i64 %a, 7
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  %2 = shl i64 %b, 57
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  %3 = or i64 %2, %1
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  ret i64 %3
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}
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;uint64_t rshift63(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:             rshift63:
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; CHECK:             shrq    $63, {{.*}}
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; CHECK-NEXT:        leaq    ({{.*}},{{.*}}), {{.*}}
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; CHECK-NEXT:        orq     {{.*}}, {{.*}}
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define i64 @rshift63(i64 %a, i64 %b) nounwind readnone uwtable {
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  %1 = lshr i64 %a, 63
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  %2 = shl i64 %b, 1
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  %3 = or i64 %2, %1
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  ret i64 %3
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}
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