From: Taylor R Campbell <campbell@mumble.net>
Date: Wed, 16 Jan 2019 04:47:13 +0000 (+0000)
Subject: Save an instruction in multiplication with CSETM.
X-Git-Tag: mit-scheme-pucked-10.1.20~11^2~66^2~75
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=323bb75874942c820781095f0be9c4145b1f48a7;p=mit-scheme.git

Save an instruction in multiplication with CSETM.
---

diff --git a/src/compiler/machines/aarch64/rulfix.scm b/src/compiler/machines/aarch64/rulfix.scm
index 4c8bb82aa..82349f134 100644
--- a/src/compiler/machines/aarch64/rulfix.scm
+++ b/src/compiler/machines/aarch64/rulfix.scm
@@ -182,9 +182,8 @@ USA.
           ;; mask is equal to the high 64 bits of a non-overflowing
           ;; multiply, so its xor with the high 64 bits is zero iff no
           ;; overflow.
-          (LAP (MOVZ X ,mask (&U 0))
-               (CMP X ,source1 (&U 0))
-               (CINV X LT ,mask ,mask)
+          (LAP (CMP X ,source1 (&U 0))
+               (CSETM X LT ,mask)
                (CMP X ,source2 (&U 0))
                (CINV X LT ,mask ,mask)
                (ASR X ,regnum:scratch-0 ,source1 (&U ,scheme-type-width))