diff mbox series

[PULL,02/12] tests/tcg/arm: Remove test-arm-iwmmxt test

Message ID 20250210154942.3634878-3-peter.maydell@linaro.org
State Accepted
Commit 86f847a39aef93bcfbea65a702ba76762ae54d61
Headers show
Series [PULL,01/12] target/arm: deprecate the pxa2xx CPUs and iwMMXt emulation | expand

Commit Message

Peter Maydell Feb. 10, 2025, 3:49 p.m. UTC 
The test-arm-iwmmmxt test isn't testing what it thinks it's testing.

If you run it with a CPU type that supports iwMMXt then it will crash
immediately with a SIGILL, because (even with -marm) GCC will link it
against startup code that is in Thumb mode, and no iwMMXt CPU has
Thumb:

00010338 <_start>:
   10338:       f04f 0b00       mov.w   fp, #0
   1033c:       f04f 0e00       mov.w   lr, #0

If you run it with a CPU type which does *not* support iwMMXt, which
is what 'make check-tcg' does, then QEMU will not try to handle the
insns as iwMMXt.  Instead the translator turns them into illegal
instructions.  Then in the linux-user cpu_loop() code we identify
them as FPA11 instructions inside emulate_arm_fpa11(), because the
FPA11 happened to use the same coprocessor number as these iwMMXt
insns.  So we execute a completely different set of FPA11 insns,
which means we don't crash, but we will print garbage to stdout.
Then the test binary always exits with a 0 return code, so 'make
check-tcg' thinks the test passes.

Modern gnueabihf toolchains assume in their startup code that the CPU
is not so old as to not support Thumb, so there's no way to get them
to generate a binary that actually does what the test wants.  Since
we're deprecating iwMMXt emulation anyway, it's not worth trying to
salvage the test case to get it to really test the iwMMXt insns.

Delete the test entirely.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20250127112715.2936555-3-peter.maydell@linaro.org
---
 tests/tcg/arm/Makefile.target   |  7 -----
 tests/tcg/arm/README            |  5 ----
 tests/tcg/arm/test-arm-iwmmxt.S | 49 ---------------------------------
 3 files changed, 61 deletions(-)
 delete mode 100644 tests/tcg/arm/test-arm-iwmmxt.S
diff mbox series

Patch

diff --git a/tests/tcg/arm/Makefile.target b/tests/tcg/arm/Makefile.target
index 06ddf3e04fc..99a953b6671 100644
--- a/tests/tcg/arm/Makefile.target
+++ b/tests/tcg/arm/Makefile.target
@@ -20,13 +20,6 @@  ARM_TESTS = hello-arm
 hello-arm: CFLAGS+=-marm -ffreestanding -fno-stack-protector
 hello-arm: LDFLAGS+=-nostdlib
 
-# IWMXT floating point extensions
-ARM_TESTS += test-arm-iwmmxt
-# Clang assembler does not support IWMXT, so use the external assembler.
-test-arm-iwmmxt: CFLAGS += -marm -march=iwmmxt -mabi=aapcs -mfpu=fpv4-sp-d16 $(CROSS_CC_HAS_FNIA)
-test-arm-iwmmxt: test-arm-iwmmxt.S
-	$(CC) $(CFLAGS) -Wa,--noexecstack $< -o $@ $(LDFLAGS)
-
 # Float-convert Tests
 ARM_TESTS += fcvt
 fcvt: LDFLAGS += -lm
diff --git a/tests/tcg/arm/README b/tests/tcg/arm/README
index e6307116e23..aceccc127f7 100644
--- a/tests/tcg/arm/README
+++ b/tests/tcg/arm/README
@@ -4,8 +4,3 @@  hello-arm
 ---------
 
 A very simple inline assembly, write syscall based hello world
-
-test-arm-iwmmxt
----------------
-
-A simple test case for older iwmmxt extended ARMs
diff --git a/tests/tcg/arm/test-arm-iwmmxt.S b/tests/tcg/arm/test-arm-iwmmxt.S
deleted file mode 100644
index d647f9404ae..00000000000
--- a/tests/tcg/arm/test-arm-iwmmxt.S
+++ /dev/null
@@ -1,49 +0,0 @@ 
-@ Checks whether iwMMXt is functional.
-.code	32
-.globl	main
-
-main:
-ldr	r0, =data0
-ldr	r1, =data1
-ldr	r2, =data2
-#ifndef FPA
-wldrd	wr0, [r0, #0]
-wldrd	wr1, [r0, #8]
-wldrd	wr2, [r1, #0]
-wldrd	wr3, [r1, #8]
-wsubb	wr2, wr2, wr0
-wsubb	wr3, wr3, wr1
-wldrd	wr0, [r2, #0]
-wldrd	wr1, [r2, #8]
-waddb	wr0, wr0, wr2
-waddb	wr1, wr1, wr3
-wstrd	wr0, [r2, #0]
-wstrd	wr1, [r2, #8]
-#else
-ldfe	f0, [r0, #0]
-ldfe	f1, [r0, #8]
-ldfe	f2, [r1, #0]
-ldfe	f3, [r1, #8]
-adfdp	f2, f2, f0
-adfdp	f3, f3, f1
-ldfe	f0, [r2, #0]
-ldfe	f1, [r2, #8]
-adfd	f0, f0, f2
-adfd	f1, f1, f3
-stfe	f0, [r2, #0]
-stfe	f1, [r2, #8]
-#endif
-mov	r0, #1
-mov	r1, r2
-mov	r2, #0x11
-swi	#0x900004
-mov	r0, #0
-swi	#0x900001
-
-.data
-data0:
-.string	"aaaabbbbccccdddd"
-data1:
-.string	"bbbbccccddddeeee"
-data2:
-.string	"hvLLWs\x1fsdrs9\x1fNJ-\n"