Re: [PATCH 1/2] tests/tcg/ppc64le: Added an overflow with OE=1 test

2022-08-18 Thread Lucas Mateus Martins Araujo e Castro 


On 18/08/2022 12:32, Richard Henderson wrote:

On 8/17/22 09:57, Lucas Mateus Castro(alqotel) wrote:

+void sigfpe_handler(int sig, siginfo_t *si, void *ucontext)
+{
+    uint64_t t;
+    uint64_t ch = 0x5fcfffe4965a17e0ull;
+    asm (
+    "stfd 2, %0\n\t"
+    : "=m"(t)
+    :
+    : "memory", "fr2"
+    );


No, you need to fetch f2 from ucontext.  There's no guarantee of any 
specific values being

present in the signal handler otherwise.
Yeah, for some reason I completely forgot about this, my bad. I'll send 
a second version fixing this



+    return -1;


exit(-1), which return from main equates to, helpful over EXIT_FAILURE.
But here I'd tend to abort(), since it really shouldn't be reachable.

Good point, I'll change in v2



r~

--
Lucas Mateus M. Araujo e Castro
Instituto de Pesquisas ELDORADO 


Departamento Computação Embarcada
Analista de Software Trainee
Aviso Legal - Disclaimer

Re: [PATCH 1/2] tests/tcg/ppc64le: Added an overflow with OE=1 test

2022-08-18 Thread Richard Henderson 

On 8/17/22 09:57, Lucas Mateus Castro(alqotel) wrote:

+void sigfpe_handler(int sig, siginfo_t *si, void *ucontext)
+{
+uint64_t t;
+uint64_t ch = 0x5fcfffe4965a17e0ull;
+asm (
+"stfd 2, %0\n\t"
+: "=m"(t)
+:
+: "memory", "fr2"
+);


No, you need to fetch f2 from ucontext.  There's no guarantee of any specific values being 
present in the signal handler otherwise.



+return -1;


exit(-1), which return from main equates to, helpful over EXIT_FAILURE.
But here I'd tend to abort(), since it really shouldn't be reachable.


r~

[PATCH 1/2] tests/tcg/ppc64le: Added an overflow with OE=1 test

2022-08-17 Thread Lucas Mateus Castro(alqotel) 
From: "Lucas Mateus Castro (alqotel)" 

Added a test to see if the adjustment is being made correctly when an
overflow occurs and OE is set.

Signed-off-by: Lucas Mateus Castro (alqotel) 
---
The prctl patch is not ready yet, so this patch does as Richard
Henderson suggested and check the fp register in the signal handler

This patch will fail without the overflow with OE set bugfix
Message-Id:<20220805141522.412864-3-lucas.ara...@eldorado.org.br>
---
 tests/tcg/ppc64/Makefile.target   |  1 +
 tests/tcg/ppc64le/Makefile.target |  1 +
 tests/tcg/ppc64le/oe_excp.c   | 54 +++
 3 files changed, 56 insertions(+)
 create mode 100644 tests/tcg/ppc64le/oe_excp.c

diff --git a/tests/tcg/ppc64/Makefile.target b/tests/tcg/ppc64/Makefile.target
index 331fae628e..43958ad87b 100644
--- a/tests/tcg/ppc64/Makefile.target
+++ b/tests/tcg/ppc64/Makefile.target
@@ -29,5 +29,6 @@ run-plugin-sha512-vector-with-%: QEMU_OPTS+=-cpu POWER10
 
 PPC64_TESTS += signal_save_restore_xer
 PPC64_TESTS += xxspltw
+PPC64_TESTS += oe_excp
 
 TESTS += $(PPC64_TESTS)
diff --git a/tests/tcg/ppc64le/Makefile.target 
b/tests/tcg/ppc64le/Makefile.target
index 6ca3003f02..8d11ac731d 100644
--- a/tests/tcg/ppc64le/Makefile.target
+++ b/tests/tcg/ppc64le/Makefile.target
@@ -27,5 +27,6 @@ PPC64LE_TESTS += mtfsf
 PPC64LE_TESTS += mffsce
 PPC64LE_TESTS += signal_save_restore_xer
 PPC64LE_TESTS += xxspltw
+PPC64LE_TESTS += oe_excp
 
 TESTS += $(PPC64LE_TESTS)
diff --git a/tests/tcg/ppc64le/oe_excp.c b/tests/tcg/ppc64le/oe_excp.c
new file mode 100644
index 00..cfc364f5ed
--- /dev/null
+++ b/tests/tcg/ppc64le/oe_excp.c
@@ -0,0 +1,54 @@
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#define FP_OE (1ull << 6)
+#define MTFSF(FLM, FRB) asm volatile ("mtfsf %0, %1" :: "i" (FLM), "f" (FRB))
+
+void sigfpe_handler(int sig, siginfo_t *si, void *ucontext)
+{
+uint64_t t;
+uint64_t ch = 0x5fcfffe4965a17e0ull;
+asm (
+"stfd 2, %0\n\t"
+: "=m"(t)
+:
+: "memory", "fr2"
+);
+if (t == ch) {
+exit(0);
+}
+fprintf(stderr, "expected result: %lx\n result: %lx\n", ch, t);
+exit(1);
+}
+
+int main()
+{
+uint64_t fpscr;
+uint64_t a = 0x7fdfffe816d77b00ull;
+uint64_t b = 0x7fdfffFC7F7FFF00ull;
+
+struct sigaction sa = {
+.sa_sigaction = sigfpe_handler,
+.sa_flags = SA_SIGINFO
+};
+
+prctl(PR_SET_FPEXC, PR_FP_EXC_PRECISE);
+sigaction(SIGFPE, , NULL);
+
+fpscr = FP_OE;
+MTFSF(0b, fpscr);
+
+asm (
+"lfd 0, %0\n\t"
+"lfd 1, %1\n\t"
+"fmul 2, 0, 1\n\t"
+:
+: "m"(a), "m"(b)
+: "memory", "fr0", "fr1", "fr2"
+);
+
+return -1;
+}
-- 
2.31.1