This patch checks the type of the lhs operand of a floating point
comparison for ARM, and commutes the operands if it is #0.0. It allows
us to optimize a comparison with zero, as the vcmp instruction
accepts #0.0 as rhs operand.
Code before for "0.0 < 0.123":
------------------------------
movw ip, #29360
movt ip, #37224
movw r9, #31981
movt r9, #16319
vmov d0, ip, r9
mov ip, #0
vmov d1, ip, ip
vcmp.f64 d1, d0
vmrs APSR, FPSCR
bcc +12
Code after:
-----------
movw ip, #29360
movt ip, #37224
movw r9, #31981
movt r9, #16319
vmov d0, ip, r9
vcmp.f64 d0, #0.0
vmrs APSR, FPSCR
bgt +12
BUG=
Review URL: https://codereview.chromium.org/1361913003
Cr-Commit-Position: refs/heads/master@{#30911}
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