Commit Graph

4 Commits

Author SHA1 Message Date
Lucas Mateus Castro (alqotel)
00d3880251 test/tcg/ppc64le: test mtfsf
Added tests for the mtfsf to check if FI bit of FPSCR is being set
and if exception calls are being made correctly.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Lucas Mateus Castro (alqotel) <lucas.araujo@eldorado.org.br>
Message-Id: <20211201163808.440385-3-lucas.araujo@eldorado.org.br>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
2021-12-17 17:57:13 +01:00
Matheus Ferst
66c6b40aba linux-user/ppc: Fix XER access in save/restore_user_regs
We should use cpu_read_xer/cpu_write_xer to save/restore the complete
register since some of its bits are in other fields of CPUPPCState. A
test is added to prevent future regressions.

Fixes: da91a00f19 ("target-ppc: Split out SO, OV, CA fields from XER")
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20211014223234.127012-2-matheus.ferst@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-10-21 11:42:47 +11:00
Matheus Ferst
ec9ad11d69 tests/tcg/ppc64le: tests for brh/brw/brd
Tests for Byte-Reverse Halfword, Word and Doubleword

Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Tested-by: Fabiano Rosas <farosas@linux.ibm.com>
[AJB: tweak to make rules for skip/plugins]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210423205757.1752480-3-matheus.ferst@eldorado.org.br>
Message-Id: <20210512102051.12134-28-alex.bennee@linaro.org>
2021-05-18 09:36:21 +01:00
Fabiano Rosas
936fda4d77 target/ppc: Fix bcdsub. emulation when result overflows
The commit d03b174a83 (target/ppc: simplify bcdadd/sub functions)
meant to simplify some of the code but it inadvertently altered the
way the CR6 field is set after the operation has overflowed.

The CR6 bits are set based on the *unbounded* result of the operation,
so we need to look at the result before returning from bcd_add_mag,
otherwise we will look at 0 when it overflows.

Consider the following subtraction:

v0 = 0x9999999999999999999999999999999c (maximum positive BCD value)
v1 = 0x0000000000000000000000000000001d (negative one BCD value)
bcdsub. v0,v0,v1,0

The Power ISA 2.07B says:
If the unbounded result is greater than zero, do the following.
  If PS=0, the sign code of the result is set to 0b1100.
  If PS=1, the sign code of the result is set to 0b1111.
  If the operation overflows, CR field 6 is set to 0b0101. Otherwise,
  CR field 6 is set to 0b0100.

POWER9 hardware:
vr0 = 0x0000000000000000000000000000000c (positive zero BCD value)
cr6 = 0b0101 (0x5) (positive, overflow)

QEMU:
vr0 = 0x0000000000000000000000000000000c (positive zero BCD value)
cr6 = 0b0011 (0x3) (zero, overflow) <--- wrong

This patch reverts the part of d03b174a83 that introduced the
problem and adds a test-case to avoid further regressions:

before:
$ make run-tcg-tests-ppc64le-linux-user
(...)
  TEST    bcdsub on ppc64le
bcdsub: qemu/tests/tcg/ppc64le/bcdsub.c:58: test_bcdsub_gt:
Assertion `(cr >> 4) == ((1 << 2) | (1 << 0))' failed.

Fixes: d03b174a83 (target/ppc: simplify bcdadd/sub functions)
Reported-by: Paul Clarke <pc@us.ibm.com>
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20210222194035.2723056-1-farosas@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2021-03-10 09:07:09 +11:00