;; Both functions in this testcase should codegen to the same function, and ;; neither of them should require spilling anything to the stack. ; RUN: llvm-upgrade < %s | llvm-as | llc -march=x86 -stats |& \ ; RUN: not grep {Number of register spills} ;; This can be compiled to use three registers if the loads are not ;; folded into the multiplies, 2 registers otherwise. int %regpressure1(int* %P) { %A = load int* %P %Bp = getelementptr int* %P, int 1 %B = load int* %Bp %s1 = mul int %A, %B %Cp = getelementptr int* %P, int 2 %C = load int* %Cp %s2 = mul int %s1, %C %Dp = getelementptr int* %P, int 3 %D = load int* %Dp %s3 = mul int %s2, %D %Ep = getelementptr int* %P, int 4 %E = load int* %Ep %s4 = mul int %s3, %E %Fp = getelementptr int* %P, int 5 %F = load int* %Fp %s5 = mul int %s4, %F %Gp = getelementptr int* %P, int 6 %G = load int* %Gp %s6 = mul int %s5, %G %Hp = getelementptr int* %P, int 7 %H = load int* %Hp %s7 = mul int %s6, %H %Ip = getelementptr int* %P, int 8 %I = load int* %Ip %s8 = mul int %s7, %I %Jp = getelementptr int* %P, int 9 %J = load int* %Jp %s9 = mul int %s8, %J ret int %s9 } ;; This testcase should produce identical code to the test above. int %regpressure2(int* %P) { %A = load int* %P %Bp = getelementptr int* %P, int 1 %B = load int* %Bp %Cp = getelementptr int* %P, int 2 %C = load int* %Cp %Dp = getelementptr int* %P, int 3 %D = load int* %Dp %Ep = getelementptr int* %P, int 4 %E = load int* %Ep %Fp = getelementptr int* %P, int 5 %F = load int* %Fp %Gp = getelementptr int* %P, int 6 %G = load int* %Gp %Hp = getelementptr int* %P, int 7 %H = load int* %Hp %Ip = getelementptr int* %P, int 8 %I = load int* %Ip %Jp = getelementptr int* %P, int 9 %J = load int* %Jp %s1 = mul int %A, %B %s2 = mul int %s1, %C %s3 = mul int %s2, %D %s4 = mul int %s3, %E %s5 = mul int %s4, %F %s6 = mul int %s5, %G %s7 = mul int %s6, %H %s8 = mul int %s7, %I %s9 = mul int %s8, %J ret int %s9 } ;; adds should be the same as muls. int %regpressure3(short* %P, bool %Cond, int* %Other) { %A = load short* %P %Bp = getelementptr short* %P, int 1 %B = load short* %Bp %Cp = getelementptr short* %P, int 2 %C = load short* %Cp %Dp = getelementptr short* %P, int 3 %D = load short* %Dp %Ep = getelementptr short* %P, int 4 %E = load short* %Ep %Fp = getelementptr short* %P, int 5 %F = load short* %Fp %Gp = getelementptr short* %P, int 6 %G = load short* %Gp %Hp = getelementptr short* %P, int 7 %H = load short* %Hp %Ip = getelementptr short* %P, int 8 %I = load short* %Ip %Jp = getelementptr short* %P, int 9 %J = load short* %Jp ;; These casts prevent folding the loads into the adds. %A = cast short %A to int %B = cast short %B to int %D = cast short %D to int %C = cast short %C to int %E = cast short %E to int %F = cast short %F to int %G = cast short %G to int %H = cast short %H to int %I = cast short %I to int %J = cast short %J to int %s1 = add int %A, %B %s2 = add int %C, %s1 %s3 = add int %D, %s2 %s4 = add int %E, %s3 %s5 = add int %F, %s4 %s6 = add int %G, %s5 %s7 = add int %H, %s6 %s8 = add int %I, %s7 %s9 = add int %J, %s8 ret int %s9 }