JIT fails to constant fold multiplies, and/or merge shifts #43551
Description
[MethodImpl(MethodImplOptions.NoInlining)]
static int Y(int x) => x * 2 * 2;produces
; Assembly listing for method X:Y(int):int
; Emitting BLENDED_CODE for X64 CPU with AVX - Windows
; optimized code
; rsp based frame
; partially interruptible
; Final local variable assignments
;
; V00 arg0 [V00,T00] ( 3, 3 ) int -> rcx
;# V01 OutArgs [V01 ] ( 1, 1 ) lclBlk ( 0) [rsp+0x00] "OutgoingArgSpace"
;
; Lcl frame size = 0
G_M5754_IG01: ;; offset=0000H
;; bbWeight=1 PerfScore 0.00
G_M5754_IG02: ;; offset=0000H
8D0409 lea eax, [rcx+rcx]
03C0 add eax, eax
;; bbWeight=1 PerfScore 0.75
G_M5754_IG03: ;; offset=0005H
C3 ret
;; bbWeight=1 PerfScore 1.00
; Total bytes of code 6, prolog size 0, PerfScore 2.35, instruction count 3 (MethodHash=7c40e985) for method X:Y(int):intShould be simple enough to handle this in morph. Or we could re-associate better.
category:cq
theme:expression-opts
skill-level:intermediate
cost:medium