From: Julien Grall Date: Tue, 19 Mar 2019 23:27:53 +0000 (+0000) Subject: xen/arm64: head: Combine lsl and str instructions in a single one X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~2281 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=842a7c7b4a58c7dcad60ad831e0af93acd4d2eb0;p=xen.git xen/arm64: head: Combine lsl and str instructions in a single one We can optimize a bit the assembly code by combining the 2 instructions in a single one. This likely not going to make the code faster, but likely make easier to read the assembly. Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini --- diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S index 0b7f6e7f92..4589a37874 100644 --- a/xen/arch/arm/arm64/head.S +++ b/xen/arch/arm/arm64/head.S @@ -418,8 +418,7 @@ skip_bss: mov x3, #PT_PT /* x2 := table map of boot_first_id */ orr x2, x2, x3 /* + rights for linear PT */ - lsl x1, x1, #3 /* x1 := Slot offset */ - str x2, [x4, x1] + str x2, [x4, x1, lsl #3] load_paddr x4, boot_first_id @@ -428,8 +427,7 @@ skip_bss: mov x3, #PT_MEM /* x2 := Section map */ orr x2, x2, x3 and x1, x1, #LPAE_ENTRY_MASK /* x1 := Slot offset */ - lsl x1, x1, #3 - str x2, [x4, x1] /* Mapping of paddr(start) */ + str x2, [x4, x1, lsl #3] /* Mapping of paddr(start) */ mov x25, #1 /* x25 := identity map now in place */ 1: /* Setup boot_first: */ @@ -450,8 +448,7 @@ skip_bss: lsl x2, x2, #FIRST_SHIFT /* Base address for 1GB mapping */ mov x3, #PT_MEM /* x2 := Section map */ orr x2, x2, x3 - lsl x1, x1, #3 /* x1 := Slot offset */ - str x2, [x4, x1] /* Create mapping of paddr(start)*/ + str x2, [x4, x1, lsl #3] /* Create mapping of paddr(start)*/ mov x25, #1 /* x25 := identity map now in place */ 1: /* Setup boot_second: */ @@ -473,8 +470,7 @@ skip_bss: lsl x2, x2, #SECOND_SHIFT /* Base address for 2MB mapping */ mov x3, #PT_MEM /* x2 := Section map */ orr x2, x2, x3 - lsl x1, x1, #3 /* x1 := Slot offset */ - str x2, [x4, x1] /* Create mapping of paddr(start)*/ + str x2, [x4, x1, lsl #3] /* Create mapping of paddr(start)*/ mov x25, #1 /* x25 := identity map now in place */ 1: /* Setup boot_third: */