From cc2ccbcedd20d4d800b5e1a79c98f2c3ad6c9bf2 Mon Sep 17 00:00:00 2001 From: Bernd Schmidt Date: Sun, 24 Nov 2019 13:08:27 +0000 Subject: Fix ix86 rtx costs for the pr30315 testcase (PR target/30315) * config/i386/i386.c (ix86_rtx_costs): Handle care of a PLUS in a COMPARE, representing an overflow detection. From-SVN: r278654 --- gcc/config/i386/i386.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'gcc/config') diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 780ebb8..04cbbd5 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -19501,6 +19501,15 @@ ix86_rtx_costs (rtx x, machine_mode mode, int outer_code_i, int opno, return true; } + if (GET_CODE (XEXP (x, 0)) == PLUS + && rtx_equal_p (XEXP (XEXP (x, 0), 0), XEXP (x, 1))) + { + /* This is an overflow detection, count it as a normal compare. */ + *total = rtx_cost (XEXP (x, 0), GET_MODE (XEXP (x, 0)), + COMPARE, 0, speed); + return true; + } + /* The embedded comparison operand is completely free. */ if (!general_operand (XEXP (x, 0), GET_MODE (XEXP (x, 0))) && XEXP (x, 1) == const0_rtx) -- cgit v1.1