MdePkg/BaseMemoryLibOptDxe: replace deprecated uses of IT blocks

The ARM architecture version 8 deprecates all uses of the IT instruction
except cases where it is followed by a single narrow instruction. So
replace any occurrences with equivalent sequences that adhere to the
new rules.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Liming Gao <liming.gao@intel.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.S b/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.S
index add04443b2..2d8f4d5b86 100644
--- a/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.S
+++ b/MdePkg/Library/BaseMemoryLibOptDxe/Arm/SetMem.S
@@ -73,15 +73,17 @@ ASM_PFX(InternalMemZeroMem):
     cmp     r4, #4                  // between 4 and 15 bytes?

     blt     4f

     cmp     r4, #8                  // between 8 and 15 bytes?

-    str     r2, [lr, #-16]          // overlapping store of 4 + (4 + 4) + 4 bytes

-    itt     gt

-    strgt   r3, [lr, #-12]

-    strgt   r2, [r1]

+    sub     r4, lr, #16

+    str     r2, [r4]                // overlapping store of 4 + (4 + 4) + 4 bytes

+    it      gt

+    strgt.n r3, [r4, #4]

+    it      gt

+    strgt.n r2, [r1]

     str     r3, [r1, #4]

     pop     {r4, pc}

 

 4:  cmp     r4, #2                  // 2 or 3 bytes?

     strb    r2, [lr, #-16]          // store 1 byte

     it      ge

-    strhge  r2, [r1, #6]            // store 2 bytes

+    strhge.n r2, [r1, #6]           // store 2 bytes

     pop     {r4, pc}