; RUN: llc < %s -march=x86-64 -mcpu=bdver1 | FileCheck %s ; clang -Oz -c test1.cpp -emit-llvm -S -o ; Verify that we generate shld insruction when we are optimizing for size, ; even for X86_64 processors that are known to have poor latency double ; precision shift instructions. ; uint64_t lshift10(uint64_t a, uint64_t b) ; { ; return (a << 10) | (b >> 54); ; } ; Function Attrs: minsize nounwind optsize readnone uwtable define i64 @_Z8lshift10mm(i64 %a, i64 %b) #0 { entry: ; CHECK: shldq $10 %shl = shl i64 %a, 10 %shr = lshr i64 %b, 54 %or = or i64 %shr, %shl ret i64 %or } attributes #0 = { minsize nounwind optsize readnone uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" } ; clang -Os -c test2.cpp -emit-llvm -S ; Verify that we generate shld insruction when we are optimizing for size, ; even for X86_64 processors that are known to have poor latency double ; precision shift instructions. ; uint64_t lshift11(uint64_t a, uint64_t b) ; { ; return (a << 11) | (b >> 53); ; } ; Function Attrs: nounwind optsize readnone uwtable define i64 @_Z8lshift11mm(i64 %a, i64 %b) #1 { entry: ; CHECK: shldq $11 %shl = shl i64 %a, 11 %shr = lshr i64 %b, 53 %or = or i64 %shr, %shl ret i64 %or } attributes #1 = { nounwind optsize readnone uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" } ; clang -O2 -c test2.cpp -emit-llvm -S ; Verify that we do not generate shld insruction when we are not optimizing ; for size for X86_64 processors that are known to have poor latency double ; precision shift instructions. ; uint64_t lshift12(uint64_t a, uint64_t b) ; { ; return (a << 12) | (b >> 52); ; } ; Function Attrs: nounwind optsize readnone uwtable define i64 @_Z8lshift12mm(i64 %a, i64 %b) #2 { entry: ; CHECK: shlq $12 ; CHECK-NEXT: shrq $52 %shl = shl i64 %a, 12 %shr = lshr i64 %b, 52 %or = or i64 %shr, %shl ret i64 %or } attributes #2= { nounwind readnone uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }