Commit 8dea08e8 authored by Tom Tan's avatar Tom Tan Committed by Commit Bot

[Win][ARM64] Fix shift mask constant for LLP64

Windows ARM64 does cross build for V8 and runs snapshot tool on build host
under simulator. Simulator is built with LLP64 data model so 0xFFFFL is 32-bit
long by default. It causes problem for the expression "0xFFFFL << shift" when
shift is 32, which actually does nothing on x64 because 0xFFFFL is only 32-bit.
The issue happens for instruction "movk rd, NUM lsl 32" which is simulated in

Simulator::VisitMoveWideImmediate. "0xFFFL << shift" acts as mask to clear bits
32-47 of the orignal value in rd. Under LLP64, the mask happens unexpectedly to
the lowest 16 bits of rd register and corrupts the result of rd. Specify 0xFFFFL
as 64 bit as 0xFFFFLL fixes this problem.

Bug: chromium:893460
Change-Id: Ibd911ce595e83637432a3e1f79a9bf28fcbe09f6
Reviewed-on: https://chromium-review.googlesource.com/c/1475330
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: 's avatarJaroslav Sevcik <jarin@chromium.org>
Reviewed-by: 's avatarJakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59778}
parent 948c1718
......@@ -2278,7 +2278,8 @@ void Simulator::VisitMoveWideImmediate(Instruction* instr) {
unsigned reg_code = instr->Rd();
int64_t prev_xn_val = is_64_bits ? xreg(reg_code)
: wreg(reg_code);
new_xn_val = (prev_xn_val & ~(0xFFFFL << shift)) | shifted_imm16;
new_xn_val =
(prev_xn_val & ~(INT64_C(0xFFFF) << shift)) | shifted_imm16;
break;
}
case MOVZ_w:
......
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